Tissue thickness compensator comprising controlled release and expansion

ABSTRACT

A tissue thickness compensator may generally comprise a first layer comprising a first biocompatible material sealingly enclosed in a water impermeable material and a second layer comprising a second biocompatible material comprising at least one encapsulation, wherein the first biocompatible material expands when contacted with a fluid. The tissue thickness compensator may comprise a haemostatic agent, an anti-inflammatory agent, an antibiotic agent, anti-microbial agent, an anti-adhesion agent, an anti-coagulant agent, a medicament, and/or pharmaceutically active agent. The encapsulation may comprise a biodegradable material to degrade in vivo and/or in situ. The tissue thickness compensator may comprise a hydrogel. The reaction product may comprise a fluid-swellable composition. Articles of manufacture comprising the tissue thickness compensator and methods of making and using the tissue thickness compensator are also described.

CROSS-REFERENCE TO RELATED APPLICATIONS

This non-provisional patent application is a continuation-in-partapplication under 35 U.S.C. § 120 of U.S. patent application Ser. No.13/097,891, entitled “Tissue Thickness Compensator For A SurgicalStapler Comprising An Adjustable Anvil”, filed on Apr. 29, 2011, nowU.S. Pat. No. 8,864,009, which is a continuation-in-part applicationunder 35 U.S.C. § 120 of U.S. patent application Ser. No. 12/894,377,entitled “Selectively Orientable Implantable Fastener Cartridge”, filedon Sep. 30, 2010, now U.S. Pat. No. 8,393,514, the entire disclosures ofwhich are hereby incorporated by reference herein.

BACKGROUND

The present invention relates to surgical instruments and, in variousembodiments, to surgical cutting and stapling instruments and staplecartridges therefor that are designed to cut and staple tissue.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and advantages of this invention, and the manner ofattaining them, will become more apparent and the invention itself willbe better understood by reference to the following description ofembodiments of the invention taken in conjunction with the accompanyingdrawings, wherein:

FIG. 1 is a cross-sectional view of a surgical instrument embodiment;

FIG. 1A is a perspective view of one embodiment of an implantable staplecartridge;

FIGS. 1B-1E illustrate portions of an end effector clamping and staplingtissue with an implantable staple cartridge;

FIG. 2 is a partial cross-sectional side view of another end effectorcoupled to a portion of a surgical instrument with the end effectorsupporting a surgical staple cartridge and with the anvil thereof in anopen position;

FIG. 3 is another partial cross-sectional side view of the end effectorof FIG. 2 in a closed position;

FIG. 4 is another partial cross-sectional side view of the end effectorof FIGS. 2 and 3 as the knife bar is starting to advance through the endeffector;

FIG. 5 is another partial cross-sectional side view of the end effectorof FIGS. 2-4 with the knife bar partially advanced therethrough;

FIGS. 6A-6D diagram the deformation of a surgical staple positionedwithin a collapsible staple cartridge body in accordance with at leastone embodiment;

FIG. 7A is a diagram illustrating a staple positioned in a crushablestaple cartridge body;

FIG. 7B is a diagram illustrating the crushable staple cartridge body ofFIG. 7A being crushed by an anvil;

FIG. 7C is a diagram illustrating the crushable staple cartridge body ofFIG. 7A being further crushed by the anvil;

FIG. 7D is a diagram illustrating the staple of FIG. 7A in a fullyformed configuration and the crushable staple cartridge of FIG. 7A in afully crushed condition;

FIG. 8 is a top view of a staple cartridge in accordance with at leastone embodiment comprising staples embedded in a collapsible staplecartridge body;

FIG. 9 is an elevational view of the staple cartridge of FIG. 8;

FIG. 10 is an exploded perspective view of an alternative embodiment ofa compressible staple cartridge comprising staples therein and a systemfor driving the staples against an anvil;

FIG. 10A is a partial cut-away view of an alternative embodiment of thestaple cartridge of FIG. 10;

FIG. 11 is a cross-sectional view of the staple cartridge of FIG. 10;

FIG. 12 is an elevational view of a sled configured to traverse thestaple cartridge of FIG. 10 and move the staples to toward the anvil;

FIG. 13 is a diagram of a staple driver which can be lifted toward theanvil by the sled of FIG. 12;

FIG. 14 is a perspective view of a staple cartridge comprising a rigidsupport portion and a compressible tissue thickness compensator for usewith a surgical stapling instrument in accordance with at least oneembodiment of the invention;

FIG. 15 is a partially exploded view of the staple cartridge of FIG. 14;

FIG. 16 is a fully exploded view of the staple cartridge of FIG. 14;

FIG. 17 is another exploded view of the staple cartridge of FIG. 14without a warp covering the tissue thickness compensator;

FIG. 18 is a perspective view of a cartridge body, or support portion,of the staple cartridge of FIG. 14;

FIG. 19 is a top perspective view of a sled movable within the staplecartridge of FIG. 14 to deploy staples from the staple cartridge;

FIG. 20 is a bottom perspective view of the sled of FIG. 19;

FIG. 21 is an elevational view of the sled of FIG. 19;

FIG. 22 is a top perspective view of a driver configured to support oneor more staples and to be lifted upwardly by the sled of FIG. 19 toeject the staples from the staple cartridge;

FIG. 23 is a bottom perspective view of the driver of FIG. 22;

FIG. 24 is a wrap configured to at least partially surround acompressible tissue thickness compensator of a staple cartridge;

FIG. 25 is a partial cut away view of a staple cartridge comprising arigid support portion and a compressible tissue thickness compensatorillustrated with staples being moved from an unfired position to a firedposition during a first sequence;

FIG. 26 is an elevational view of the staple cartridge of FIG. 25;

FIG. 27 is a detail elevational view of the staple cartridge of FIG. 25;

FIG. 28 is a cross-sectional end view of the staple cartridge of FIG.25;

FIG. 29 is a bottom view of the staple cartridge of FIG. 25;

FIG. 30 is a detail bottom view of the staple cartridge of FIG. 25;

FIG. 31 is a longitudinal cross-sectional view of an anvil in a closedposition and a staple cartridge comprising a rigid support portion and acompressible tissue thickness compensator illustrated with staples beingmoved from an unfired position to a fired position during a firstsequence;

FIG. 32 is another cross-sectional view of the anvil and the staplecartridge of FIG. 31 illustrating the anvil in an open position afterthe firing sequence has been completed;

FIG. 33 is a partial detail view of the staple cartridge of FIG. 31illustrating the staples in an unfired position;

FIG. 34 is a cross-sectional elevational view of a staple cartridgecomprising a rigid support portion and a compressible tissue thicknesscompensator illustrating the staples in an unfired position;

FIG. 35 is a detail view of the staple cartridge of FIG. 34;

FIG. 36 is an elevational view of an anvil in an open position and astaple cartridge comprising a rigid support portion and a compressibletissue thickness compensator illustrating the staples in an unfiredposition;

FIG. 37 is an elevational view of an anvil in a closed position and astaple cartridge comprising a rigid support portion and a compressibletissue thickness compensator illustrating the staples in an unfiredposition and tissue captured between the anvil and the tissue thicknesscompensator;

FIG. 38 is a detail view of the anvil and staple cartridge of FIG. 37;

FIG. 39 is an elevational view of an anvil in a closed position and astaple cartridge comprising a rigid support portion and a compressibletissue thickness compensator illustrating the staples in an unfiredposition illustrating thicker tissue positioned between the anvil andthe staple cartridge;

FIG. 40 is a detail view of the anvil and staple cartridge of FIG. 39;

FIG. 41 is an elevational view of the anvil and staple cartridge of FIG.39 illustrating tissue having different thicknesses positioned betweenthe anvil and the staple cartridge;

FIG. 42 is a detail view of the anvil and staple cartridge of FIG. 39 asillustrated in FIG. 41;

FIG. 43 is a diagram illustrating a tissue thickness compensator whichis compensating for different tissue thickness captured within differentstaples;

FIG. 44 is a diagram illustrating a tissue thickness compensatorapplying a compressive pressure to one or more vessels that have beentransected by a staple line;

FIG. 45 is a diagram illustrating a circumstance wherein one or morestaples have been improperly formed;

FIG. 46 is a diagram illustrating a tissue thickness compensator whichcould compensate for improperly formed staples;

FIG. 47 is a diagram illustrating a tissue thickness compensatorpositioned in a region of tissue in which multiple staples lines haveintersected;

FIG. 48 is a diagram illustrating tissue captured within a staple;

FIG. 49 is a diagram illustrating tissue and a tissue thicknesscompensator captured within a staple;

FIG. 50 is a diagram illustrating tissue captured within a staple;

FIG. 51 is a diagram illustrating thick tissue and a tissue thicknesscompensator captured within a staple;

FIG. 52 is a diagram illustrating thin tissue and a tissue thicknesscompensator captured within a staple;

FIG. 53 is a diagram illustrating tissue having an intermediatethickness and a tissue thickness compensator captured within a staple;

FIG. 54 is a diagram illustrating tissue having another intermediatethickness and a tissue thickness compensator captured within a staple;

FIG. 55 is a diagram illustrating thick tissue and a tissue thicknesscompensator captured within a staple;

FIG. 56 is a partial cross-sectional view of an end effector of asurgical stapling instrument illustrating a firing bar and staple-firingsled in a retracted, unfired position;

FIG. 57 is another partial cross-sectional view of the end effector ofFIG. 56 illustrating the firing bar and the staple-firing sled in apartially advanced position;

FIG. 58 is a cross-sectional view of the end effector of FIG. 56illustrating the firing bar in a fully advanced, or fired, position;

FIG. 59 is a cross-sectional view of the end effector of FIG. 56illustrating the firing bar in a retracted position after being firedand the staple-firing sled left in its fully fired position;

FIG. 60 is a detail view of the firing bar in the retracted position ofFIG. 59;

FIG. 61 is a perspective view of a tissue thickness compensator in anend effector of a surgical instrument according to at least oneembodiment;

FIG. 62 is a detail view of nonwoven material of the tissue thicknesscompensator of FIG. 61;

FIG. 63 is an elevational view depicting the tissue thicknesscompensator of FIG. 61 implanted against tissue and released from theend effector;

FIG. 64 is a detail view of nonwoven material of a tissue thicknesscompensator according to at least one embodiment;

FIG. 65 is a schematic depicting clusters of randomly oriented crimpedfibers according to at least one embodiment;

FIG. 66 is a schematic depicting a cluster of randomly oriented crimpedfibers according to at least one embodiment;

FIG. 67 is a schematic depicting an arrangement of crimped fibersaccording to at least one embodiment;

FIG. 68 is a schematic depicting an arrangement of crimped fibersaccording to at least one embodiment;

FIG. 69 is a schematic depicting an arrangement of crimped fibersaccording to at least one embodiment;

FIG. 70 is a plan cross-sectional view of coiled fibers in a tissuethickness compensator according to at least one embodiment;

FIG. 70A is a plan cross-sectional view of the coiled fibers of FIG. 70;

FIG. 70B is a cross-sectional detail view of the tissue thicknesscompensator of FIG. 70;

FIG. 71 is a perspective view of a tissue thickness compensator in anend effector of a surgical instrument according to at least oneembodiment;

FIG. 72 is a diagram depicting deformation of the tissue thicknesscompensator of FIG. 71;

FIG. 73 is a schematic of woven suture for a tissue thicknesscompensator depicting the woven suture in a loaded configurationaccording to at least one embodiment;

FIG. 74 is a schematic of the woven suture of FIG. 73 depicting thewoven suture in a released configuration;

FIG. 75 is a plan view of a tissue thickness compensator having thewoven suture of FIG. 73 in an end effector of a surgical instrument;

FIG. 76 is a perspective view of a tissue thickness compensator in anend effector of a surgical instrument according to at least oneembodiment;

FIG. 77 is a partial plan view of the tissue thickness compensator ofFIG. 76;

FIG. 78 is an exploded view of the fastener cartridge assembly of theend effector and tissue thickness compensator of FIG. 61;

FIG. 79 is a partial cross-sectional view of the fastener cartridgeassembly of FIG. 78 depicting unfired, partially fired, and firedfasteners;

FIG. 80 is an elevational view of the fastener cartridge assembly ofFIG. 78 depicting a driver firing fasteners from staple cavities of thefastener cartridge assembly into the tissue thickness compensator;

FIG. 81 is a detail view of the fastener cartridge assembly of FIG. 80;

FIG. 82 is an elevational view of the tissue thickness compensator ofFIG. 61 and tissue captured within fired fasteners;

FIG. 83 is an elevational view of the tissue thickness compensator ofFIG. 61 and tissue captured within fired fasteners;

FIG. 84 is a perspective view of a tissue thickness compensator in anend effector of a surgical instrument according to at least oneembodiment;

FIG. 85 is a diagram depicting deformation of a deformable tube of thetissue thickness compensator of FIG. 84;

FIG. 86 is a detail view of the deformable tube of the tissue thicknesscompensator of FIG. 84;

FIG. 87 is a diagram depicting deformation of a deformable tube of atissue thickness compensator according to at least one embodiment;

FIG. 88 is an elevational view of a tissue thickness compensatorcomprising a tubular element implanted against tissue according to atleast one embodiment;

FIG. 89 is an elevational view of a tissue thickness compensatorcomprising tubular elements implanted against tissue according to atleast one embodiment;

FIG. 90 is a partial perspective view of a deformable tube comprising atubular lattice according to at least one embodiment;

FIG. 91 is an elevational view of a tubular strand of the deformabletube of FIG. 90.

FIG. 92 is an elevational view of the deformable tube of FIG. 90;

FIG. 93 is an elevational view of multiple tubular strands for thedeformable tube of FIG. 90 according to various embodiments;

FIG. 94 is an elevational view of the tubular lattice of FIG. 90implanted against tissue;

FIG. 95 is a partial perspective view of a deformable tube according toat least one embodiment;

FIG. 96 is a partial perspective view of a deformable tube according toat least one embodiment;

FIG. 97 is a partial perspective view of a deformable tube according toat least one embodiment;

FIG. 98 is an elevational view of the deformable tube of FIG. 97;

FIG. 99 is a partial perspective view of a deformable tube according toat least one embodiment;

FIG. 100 is a partial perspective view of a deformable tube according toat least one embodiment;

FIG. 101 is a partial perspective view of a deformable tube according toat least one embodiment;

FIG. 102 is a perspective view of a tissue thickness compensatorpositioned in an end effector of a surgical instrument according to atleast one embodiment;

FIG. 103 is an elevational view of a tubular element of the tissuethickness compensator of FIG. 102;

FIG. 104 is an elevational cross-sectional view of the tissue thicknesscompensator and the end effector of FIG. 102 depicting the end effectorin an unclamped configuration;

FIG. 105 is an elevational cross-sectional view of the tissue thicknesscompensator and the end effector of FIG. 102 depicting the end effectorin a clamped and fired configuration;

FIG. 106 is an elevational cross-sectional view of a tissue thicknesscompensator positioned in an end effector of a surgical instrumentaccording to at least one embodiment;

FIG. 107 is an elevational cross-sectional view of the tissue thicknesscompensator and the end effector of FIG. 106 depicting the end effectorin a clamped and fired configuration;

FIG. 108 is an elevational cross-sectional view of a tissue thicknesscompensator in the end effector of a surgical instrument according to atleast one embodiment;

FIG. 109 is a cross-sectional elevational view of a tissue thicknesscompensator positioned in an end effector of a surgical instrumentaccording to at least one embodiment;

FIG. 110 is a cross-sectional elevational view of the tissue thicknesscompensator and the end effector of FIG. 109 depicting the end effectorin a clamped and fired configuration;

FIG. 111 is a perspective view of a tissue thickness compensatorpositioned in an end effector of a surgical instrument according to atleast one embodiment;

FIG. 112 is an elevational cross-sectional view of a tissue thicknesscompensator positioned in an end effector of a surgical instrumentaccording to at least one embodiment;

FIG. 113 is an elevational cross-sectional view of a tissue thicknesscompensator positioned in an end effector of a surgical instrumentaccording to at least one embodiment;

FIG. 114 is an elevational cross-sectional view of a tissue thicknesscompensator positioned in an end effector of a surgical instrumentaccording to at least one embodiment;

FIG. 115 is an elevational cross-sectional view of a tissue thicknesscompensator positioned in an end effector of a surgical instrumentaccording to at least one embodiment;

FIG. 116 is a partial plan view of a tissue thickness compensatorpositioned in an end effector of a surgical instrument according to atleast one embodiment;

FIG. 117 is a partial plan view of a tissue thickness compensatorpositioned in an end effector of a surgical instrument according to atleast one embodiment;

FIG. 118 is a partial elevational cross-sectional view of the tissuethickness compensator and the end effector of FIG. 116 depicting the endeffector in an unclamped configuration;

FIG. 119 is a partial elevational cross-sectional view of the tissuethickness compensator and the end effector of FIG. 116 depicting the endeffector in a clamped configuration;

FIG. 120 is a perspective view of a tissue thickness compensator in anend effector of a surgical instrument according to at least oneembodiment;

FIG. 121 is an elevational view of the tissue thickness compensator andthe end effector of FIG. 120;

FIG. 122 is a perspective view of the tissue thickness compensator andthe end effector of FIG. 120 depicting the anvil of the end effectormoving towards a clamped configuration;

FIG. 123 is an elevational view of the tissue thickness compensator andthe end effector of FIG. 120 depicting the end effector in a clampedconfiguration;

FIG. 124 is an elevational cross-sectional view of tubular elements ofthe tissue thickness compensator of FIG. 120 in an undeformedconfiguration;

FIG. 125 is an elevational cross-sectional view of tubular elements ofthe tissue thickness compensator of FIG. 120 in a deformedconfiguration;

FIG. 126 is a perspective view of a tissue thickness compensator in anend effector of a surgical instrument according to at least oneembodiment;

FIG. 127 is an elevational cross-sectional view of the tissue thicknesscompensator and the end effector of FIG. 126 depicting the end effectorin a clamped configuration;

FIG. 128 is an elevational cross-sectional view of the tissue thicknesscompensator and the end effector of FIG. 126 depicting the end effectorin a fired and partially unclamped configuration;

FIG. 129 is a perspective view of a tissue thickness compensatorpositioned in an end effector of a surgical instrument according to atleast one embodiment;

FIG. 130 is an elevational cross-sectional view of a tissue thicknesscompensator secured to an anvil of an end effector of a surgicalinstrument according to at least one embodiment;

FIG. 131 is an elevational cross-sectional view of the tissue thicknesscompensator and the end effector of FIG. 130 depicting the end effectorin a clamped configuration;

FIG. 132 is an elevational cross-sectional view of the tissue thicknesscompensator and the end effector of FIG. 130 depicting the end effectorin a fired and partially unclamped configuration;

FIG. 133 is a detail view of the tissue thickness compensator and theend effector of FIG. 132;

FIG. 134 is an elevational cross-sectional view of a tissue thicknesscompensator clamped in an end effector of a surgical instrumentdepicting deployment of staples by a staple-firing sled according to atleast one embodiment;

FIG. 135 is an elevational cross-sectional view of the tissue thicknesscompensator and the end effector of FIG. 134 depicting the end effectorin a clamped configuration;

FIG. 136 is an elevational cross-sectional view of the tissue thicknesscompensator and the end effector of FIG. 134 depicting the end effectorin a fired configuration;

FIG. 137 is a perspective view of a tissue thickness compensator in anend effector of a surgical instrument according to at least oneembodiment;

FIG. 138 is a perspective view of a tubular element of the tissuethickness compensator of FIG. 137;

FIG. 139 is a perspective view of the tubular element of FIG. 138severed between a first and second end;

FIG. 140 is a perspective view of the tissue thickness compensator ofFIG. 137 depicting a cutting element severing the tissue thicknesscompensator and staples engaging the tissue thickness compensator;

FIG. 141 is perspective view of a frame configured to make the tissuethickness compensator of FIG. 137 according to at least one embodiment;

FIG. 142 is an elevational cross-sectional view of the frame of FIG. 141depicting the tissue thickness compensator of FIG. 137 curing in theframe;

FIG. 143 is an elevational cross-sectional view of the tissue thicknesscompensator removed from the frame of FIG. 142 and prepared for trimmingby at least one cutting instrument;

FIG. 144 is an elevational cross-sectional view of the tissue thicknesscompensator of FIG. 143 after at least one cutting instrument hastrimmed the tissue thickness compensator;

FIG. 145 is an elevational cross-sectional view of the tissue thicknesscompensator formed in the frame of FIG. 142 depicting severable tubeshaving various cross-sectional geometries;

FIG. 146 is a perspective view of a tissue thickness compensator in anend effector of a surgical instrument according to at least oneembodiment;

FIG. 147 is a detail view of the tissue thickness compensator of FIG.146 according to at least one embodiment;

FIG. 148 is a partial perspective view of a tissue thickness compensatoraccording to at least one embodiment;

FIG. 149 is a partial perspective view of a tissue thickness compensatoraccording to at least one embodiment;

FIG. 150A is an elevational cross-sectional view of the tissue thicknesscompensator and the end effector of FIG. 146 depicting the end effectorin an unclamped configuration;

FIG. 150B is an elevational cross-sectional view of the tissue thicknesscompensator and the end effector of FIG. 146 depicting the end effectorin a clamped configuration;

FIG. 150C is an elevational cross-sectional view of the tissue thicknesscompensator and the end effector of FIG. 146 depicting the end effectorin a clamped and fired configuration;

FIG. 150D is an elevational cross-sectional view of the tissue thicknesscompensator of FIG. 146 captured in fired staples;

FIG. 150E is an elevational cross-sectional view of the tissue thicknesscompensator of FIG. 146 captured in fired staples depicting furtherexpansion of the tissue thickness compensator;

FIG. 151 is a perspective cross-sectional view of a tissue thicknesscompensator in an end effector of a surgical instrument according to atleast one embodiment;

FIG. 152 is a partial elevational view of the tissue thicknesscompensator of FIG. 151 captured in a fired staple;

FIG. 153 is an elevational view of a deformable tube of the tissuethickness compensator of FIG. 151;

FIG. 154 is an elevational view of a deformable tube according to atleast one embodiment;

FIG. 155 is a perspective cross-sectional view of the tissue thicknesscompensator of FIG. 151;

FIG. 156 is a perspective cross-sectional view of a tissue thicknesscompensator in an end effector of a surgical instrument according to atleast one embodiment;

FIG. 157 is a perspective view of a tissue thickness compensatoraccording to at least one embodiment;

FIG. 158 is a partial elevational cross-sectional view of the tissuethickness compensator of FIG. 157 depicting a fastener engaged withtissue and with the tissue thickness compensator;

FIG. 159 is a perspective cross-sectional view of a tissue thicknesscompensator according to at least one embodiment;

FIG. 160 is an elevational view of a tissue thickness compensatoraccording to at least one embodiment;

FIG. 161 is an elevational view of a tissue thickness compensatoraccording to at least one embodiment;

FIG. 162 is an elevational view of a tissue thickness compensatorpositioned in a circular end effector of a surgical instrument accordingto at least one embodiment;

FIG. 163 is an elevational view of a tissue thickness compensatoraccording to at least one embodiment;

FIG. 164 is an elevational view of a tissue thickness compensatoraccording to at least one embodiment;

FIG. 165 is an elevational view of a tissue thickness compensatoraccording to at least one embodiment;

FIG. 166 is an elevational view of a tissue thickness compensatoraccording to at least one embodiment;

FIG. 167 is an elevational view of a tissue thickness compensatoraccording to at least one embodiment;

FIG. 168 is a partial perspective view of a tissue thickness compensatoraccording to at least one embodiment;

FIG. 169 is a partial perspective view of a tissue thickness compensatorpositioned in an end effector of a surgical instrument according to atleast one embodiment;

FIG. 170 is a partial perspective view of a tissue thickness compensatorwith a fastener positioned in the apertures thereof according to atleast one embodiment;

FIG. 171 is a partial perspective view of the tissue thicknesscompensator of FIG. 169 depicting the tissue thickness compensator in anundeformed configuration;

FIG. 172 is a partial perspective view of the tissue thicknesscompensator of FIG. 169 depicting the tissue thickness compensator in apartially deformed configuration;

FIG. 173 is a partial perspective view of the tissue thicknesscompensator of FIG. 169 depicting the tissue thickness compensator in adeformed configuration;

FIG. 174 is a perspective view of a tissue thickness compensatoraccording to at least one embodiment;

FIG. 175 is a perspective view of an end effector of a staplinginstrument comprising an anvil and a staple cartridge in accordance withat least one embodiment;

FIG. 176 is a cross-sectional view of the end effector of FIG. 175illustrating staples positioned within the staple cartridge in anunfired state and a tissue thickness compensator comprising a sealedvessel in an unpunctured state, wherein the vessel is depicted withportions thereof removed for the purposes of illustration;

FIG. 177 is a cross-sectional view of the end effector of FIG. 175illustrating the staples of FIG. 176 in an at least partially firedstate and the vessel in an at least partially punctured state;

FIG. 178 is a perspective view of an end effector of a staplinginstrument comprising an anvil and a staple cartridge in accordance withat least one embodiment;

FIG. 179 is a cross-sectional view of the end effector of FIG. 178illustrating staples positioned within the staple cartridge in anunfired state and sealed vessels positioned within a tissue thicknesscompensator of the staple cartridge in an unpunctured state, wherein thevessels are depicted with portions thereof removed for the purposes ofillustration;

FIG. 180 is a cross-sectional view of the end effector of FIG. 178illustrating the staples of FIG. 179 in an at least partially firedstate and the vessels in the staple cartridge in an at least partiallypunctured state;

FIG. 181 is a perspective view of an end effector of a staplinginstrument comprising an anvil and a sealed vessel attached to the anvilin accordance with at least one alternative embodiment wherein thevessel is depicted with portions thereof removed for the purposes ofillustration;

FIG. 182 is a cross-sectional view of the end effector of FIG. 181illustrating staples at least partially fired from a staple cartridgeand the vessels attached to the anvil in an at least partially puncturedstate;

FIG. 183 is a cross-sectional view of the vessel attached to the anvilof FIG. 181 illustrated in an expanded state;

FIG. 184 is a detail view of the vessel attached to the anvil of FIG.183 illustrated in an expanded state;

FIG. 185 illustrates a vessel extending in a direction transverse to aline of staples;

FIG. 186 illustrates a plurality of vessels extending in directionswhich are transverse to a line of staples;

FIG. 187 is a cross-sectional view of a staple cartridge in accordancewith various embodiments;

FIG. 188 is a partial cross-section view of FIG. 187 in an implantedcondition;

FIG. 189A is a partial perspective view of a tissue thicknesscompensator prior to expansion;

FIG. 189B is a partial perspective view of a tissue thicknesscompensator of FIG. 189 during expansion;

FIG. 190 is a partial perspective view of a tissue thickness compensatorcomprising a fluid swellable composition according to variousembodiments;

FIG. 191 is a cross-sectional view of tissue positioned adjacent atissue thickness compensator according to various embodiments;

FIG. 192 is a partial cross-sectional view of FIG. 191 after the staplecartridge has been fired;

FIG. 193 is a diagram illustrating the tissue thickness compensator ofFIG. 191 implanted adjacent the tissue;

FIG. 194 is a partial perspective view of a tissue thickness compensatoraccording to various embodiments;

FIG. 195 is a perspective view of a jaw configured to receive the tissuethickness compensator of FIG. 194;

FIG. 196 is a partial cross-sectional view of a staple cartridgeillustrating staples being deployed from the staple cartridge;

FIG. 197 is a perspective view of an upper tissue thickness compensatorand a lower tissue thickness compensator positioned within an effectorof a disposable loading unit;

FIG. 198A is a cross-sectional view of the lower tissue thicknesscompensator of FIG. 197 being manufactured in a mold in accordance withvarious embodiments;

FIG. 198B is a cross-sectional view of a trilayer tissue thicknesscompensator being manufactured in a mold in accordance with variousembodiments;

FIG. 199 is a cross-sectional view of an anvil comprising a tissuethickness compensator comprising reinforcement material in accordancewith various embodiments;

FIG. 200 is cross-sectional view of a tissue positioned intermediate theupper tissue thickness compensator and lower tissue thicknesscompensator in accordance with various embodiments;

FIG. 201 is a cross-sectional view of FIG. 200 illustrating staplesbeing deployed from the staple cartridge;

FIG. 202 is a cross-sectional view of FIG. 200 after the staplecartridge has been fired;

FIG. 203A illustrates a needle configured to deliver a fluid to a tissuethickness compensator attached to a staple cartridge according tovarious embodiments;

FIG. 203B is a cross-sectional view of a staple cartridge comprising atissue thickness compensator configured to receive the needle of FIG.203A;

FIG. 204 illustrates a method of manufacturing a tissue thicknesscompensator according to various embodiments;

FIG. 205 is a diagram and a method of forming an expanding thicknesscompensator according to various embodiments;

FIG. 206 illustrates a micelle comprising a hydrogel precursor; and

FIG. 207 is a diagram of a surgical instrument comprising a tissuethickness compensator and fluids that may be delivered to the tissuethickness compensator according to various embodiments.

FIG. 208 is a partial perspective view of a tissue thickness compensatorsecured to an anvil of an end effector of a surgical instrumentaccording to at least one embodiment.

FIG. 209 is a perspective view of a tubular element of the tissuethickness compensator of FIG. 208.

FIG. 210 is a perspective view of the tubular element of FIG. 209depicting the tubular element severed into two halves and fluidcontacting the hydrophilic substance within each half.

FIG. 211 is a perspective view of a half of the severed tubular elementof FIG. 210 depicting expansion of the severed tubular element.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplifications set out hereinillustrate certain embodiments of the invention, in one form, and suchexemplifications are not to be construed as limiting the scope of theinvention in any manner.

DETAILED DESCRIPTION

The Applicant of the present application also owns the U.S. patentapplications identified below which are each herein incorporated byreference in their respective entirety:

U.S. patent application Ser. No. 12/894,311, entitled SURGICALINSTRUMENTS WITH RECONFIGURABLE SHAFT SEGMENTS, now U.S. Pat. No.8,763,877;

U.S. patent application Ser. No. 12/894,340, entitled SURGICAL STAPLECARTRIDGES SUPPORTING NON-LINEARLY ARRANGED STAPLES AND SURGICALSTAPLING INSTRUMENTS WITH COMMON STAPLE-FORMING POCKETS, now U.S. Pat.No. 8,899,463;

U.S. patent application Ser. No. 12/894,327, entitled JAW CLOSUREARRANGEMENTS FOR SURGICAL INSTRUMENTS, now U.S. Pat. No. 8,978,956;

U.S. patent application Ser. No. 12/894,351, entitled SURGICAL CUTTINGAND FASTENING INSTRUMENTS WITH SEPARATE AND DISTINCT FASTENER DEPLOYMENTAND TISSUE CUTTING SYSTEMS, now U.S. Patent Application Publication No.2012/0080502;

U.S. patent application Ser. No. 12/894,338, entitled IMPLANTABLEFASTENER CARTRIDGE HAVING A NON-UNIFORM ARRANGEMENT, now U.S. Pat. No.8,864,007;

U.S. patent application Ser. No. 12/894,369, entitled IMPLANTABLEFASTENER CARTRIDGE COMPRISING A SUPPORT RETAINER, now U.S. PatentApplication Publication No. 2012/0080344;

U.S. patent application Ser. No. 12/894,312, entitled IMPLANTABLEFASTENER CARTRIDGE COMPRISING MULTIPLE LAYERS, now U.S. Pat. No.8,925,782;

U.S. patent application Ser. No. 12/894,377, entitled SELECTIVELYORIENTABLE IMPLANTABLE FASTENER CARTRIDGE, now U.S. Pat. No. 8,393,514;

U.S. patent application Ser. No. 12/894,339, entitled SURGICAL STAPLINGINSTRUMENT WITH COMPACT ARTICULATION CONTROL ARRANGEMENT, now U.S. Pat.No. 8,840,003;

U.S. patent application Ser. No. 12/894,360, entitled SURGICAL STAPLINGINSTRUMENT WITH A VARIABLE STAPLE FORMING SYSTEM, now U.S. PatentApplication Publication No. 2012/0080484;

U.S. patent application Ser. No. 12/894,322, entitled SURGICAL STAPLINGINSTRUMENT WITH INTERCHANGEABLE STAPLE CARTRIDGE ARRANGEMENTS, now U.S.Pat. No. 8,740,034;

U.S. patent application Ser. No. 12/894,350, entitled SURGICAL STAPLECARTRIDGES WITH DETACHABLE SUPPORT STRUCTURES AND SURGICAL STAPLINGINSTRUMENTS WITH SYSTEMS FOR PREVENTING ACTUATION MOTIONS WHEN ACARTRIDGE IS NOT PRESENT, now U.S. Patent Application Publication No.2012/0080478;

U.S. patent application Ser. No. 12/894,383, entitled IMPLANTABLEFASTENER CARTRIDGE COMPRISING BIOABSORBABLE LAYERS, now U.S. Pat. No.8,752,699;

U.S. patent application Ser. No. 12/894,389, entitled COMPRESSIBLEFASTENER CARTRIDGE , now U.S. Pat. No. 8,740,037;

U.S. patent application Ser. No. 12/894,345, entitled FASTENERSSUPPORTED BY A FASTENER CARTRIDGE SUPPORT, now U.S. Pat. No. 8,783,542;

U.S. patent application Ser. No. 12/894,306, entitled COLLAPSIBLEFASTENER CARTRIDGE, now U.S. Pat. No. 9,044,227;

U.S. patent application Ser. No. 12/894,318, entitled FASTENER SYSTEMCOMPRISING A PLURALITY OF CONNECTED RETENTION MATRIX ELEMENTS, now U.S.Pat. No. 8,814,024;

U.S. patent application Ser. No. 12/894,330, entitled FASTENER SYSTEMCOMPRISING A RETENTION MATRIX AND AN ALIGNMENT MATRIX, now U.S. Pat. No.8,757,465;

U.S. patent application Ser. No. 12/894,361, entitled FASTENER SYSTEMCOMPRISING A RETENTION MATRIX, now U.S. Pat. No. 8,529,600;

U.S. patent application Ser. No. 12/894,367, entitled FASTENINGINSTRUMENT FOR DEPLOYING A FASTENER SYSTEM COMPRISING A RETENTIONMATRIX, now U.S. Pat. No. 9,033,203;

U.S. patent application Ser. No. 12/894,388, entitled FASTENER SYSTEMCOMPRISING A RETENTION MATRIX AND A COVER, now U.S. Pat. No. 8,474,677;

U.S. patent application Ser. No. 12/894,376, entitled FASTENER SYSTEMCOMPRISING A PLURALITY OF FASTENER CARTRIDGES, now U.S. Pat. No.9,044,228;

U.S. patent application Ser. No. 13/097,865, entitled SURGICAL STAPLERANVIL COMPRISING A PLURALITY OF FORMING POCKETS, now U.S. PatentApplication Publication No. 2012/0080488;

U.S. patent application Ser. No. 13/097,936, entitled TISSUE THICKNESSCOMPENSATOR FOR A SURGICAL STAPLER, now U.S. Pat. No. 8,657,176;

U.S. patent application Ser. No. 13/097,954, entitled STAPLE CARTRIDGECOMPRISING A VARIABLE THICKNESS COMPRESSIBLE PORTION, now U.S. PatentApplication Publication No. 2012/0080340;

U.S. patent application Ser. No. 13/097,856, entitled STAPLE CARTRIDGECOMPRISING STAPLES POSITIONED WITHIN A COMPRESSIBLE PORTION THEREOF, nowU.S. Patent Application Publication No. 2012/0080336;

U.S. patent application Ser. No. 13/097,928, entitled TISSUE THICKNESSCOMPENSATOR COMPRISING DETACHABLE PORTIONS, now U.S. Pat. No. 8,746,535;

U.S. patent application Ser. No. 13/097,891, entitled TISSUE THICKNESSCOMPENSATOR FOR A SURGICAL STAPLER COMPRISING AN ADJUSTABLE ANVIL, nowU.S. Pat. No. 8,864,009;

U.S. patent application Ser. No. 13/097,948, entitled STAPLE CARTRIDGECOMPRISING AN ADJUSTABLE DISTAL PORTION, now U.S. Pat. No. 8,978,954;

U.S. patent application Ser. No. 13/097,907, entitled COMPRESSIBLESTAPLE CARTRIDGE ASSEMBLY, now U.S. Patent Application Publication No.2012/0080338;

U.S. patent application Ser. No. 13/097,861, entitled TISSUE THICKNESSCOMPENSATOR COMPRISING PORTIONS HAVING DIFFERENT PROPERTIES, now U.S.Patent Application Publication No. 2012/0080337;

U.S. patent application Ser. No. 13/097,869, entitled STAPLE CARTRIDGELOADING ASSEMBLY, now U.S. Pat. No. 8,857,694;

U.S. patent application Ser. No. 13/097,917, entitled COMPRESSIBLESTAPLE CARTRIDGE COMPRISING ALIGNMENT MEMBERS, now U.S. Pat. No.8,777,004;

U.S. patent application Ser. No. 13/097,873, entitled STAPLE CARTRIDGECOMPRISING A RELEASABLE PORTION, now U.S. Pat. No. 8,740,038;

U.S. patent application Ser. No. 13/097,938, entitled STAPLE CARTRIDGECOMPRISING COMPRESSIBLE DISTORTION RESISTANT COMPONENTS, now U.S. Pat.No. 9,016,542;

U.S. patent application Ser. No. 13/097,924, entitled STAPLE CARTRIDGECOMPRISING A TISSUE THICKNESS COMPENSATOR, now U.S. Patent ApplicationPublication No. 2012/0083835;

U.S. patent application Ser. No. 13/242,029, entitled SURGICAL STAPLERWITH FLOATING ANVIL, now U.S. Pat. No. 8,893,949;

U.S. patent application Ser. No. 13/242,066, entitled CURVED ENDEFFECTOR FOR A STAPLING INSTRUMENT, now U.S. Patent ApplicationPublication No. 2012/0080498;

U.S. patent application Ser. No. 13/242,086, entitled STAPLE CARTRIDGEINCLUDING COLLAPSIBLE DECK, now U.S. Pat. No. 9,055,941;

U.S. patent application Ser. No. 13/241,912, entitled STAPLE CARTRIDGEINCLUDING COLLAPSIBLE DECK ARRANGEMENT, now U.S. Pat. No. 9,050,084;

U.S. patent application Ser. No. 13/241,922, entitled SURGICAL STAPLERWITH STATIONARY STAPLE DRIVERS, now U.S. Patent Application Publication2013/0075449;

U.S. patent application Ser. No. 13/241,637, entitled SURGICALINSTRUMENT WITH TRIGGER ASSEMBLY FOR GENERATING MULTIPLE ACTUATIONMOTIONS, now U.S. Pat. No. 8,789,741; and

U.S. patent application Ser. No. 13/241,629, entitled SURGICALINSTRUMENT WITH SELECTIVELY ARTICULATABLE END EFFECTOR, now U.S. PatentApplication Publication No. 2012/0074200.

The Applicant of the present application also owns the U.S. PatentApplications identified below which were filed on Mar. 28 , 2012 andwhich are each herein incorporated by reference in their respectiveentirety:

U.S. application Ser. No. 13/433,096, entitled TISSUE THICKNESSCOMPENSATOR COMPRISING A PLURALITY OF CAPSULES, now U.S. PatentApplication Publication No. 2012/0241496;

U.S. application Ser. No. 13/433,103, entitled TISSUE THICKNESSCOMPENSATOR COMPRISING A PLURALITY OF LAYERS, now U.S. PatentApplication Publication No. 2012/0241498;

U.S. application Ser. No. 13/433,098, entitled EXPANDABLE TISSUETHICKNESS COMPENSATOR, now U.S. Patent Application Publication No.2012/0241491;

U.S. application Ser. No. 13/433,102, entitled TISSUE THICKNESSCOMPENSATOR COMPRISING A RESERVOIR, now U.S. Patent ApplicationPublication No. 2012/0241497;

U.S. application Ser. No. 13/433,114, entitled RETAINER ASSEMBLYINCLUDING A TISSUE THICKNESS COMPENSATOR, now U.S. Patent ApplicationPublication No. 2012/0241499;

U.S. application Ser. No. 13/433,136, entitled TISSUE THICKNESSCOMPENSATOR COMPRISING AT LEAST ONE MEDICAMENT, now U.S. PatentApplication Publication No. 2012/0241492;

U.S. application Ser. No. 13/433,144, entitled TISSUE THICKNESSCOMPENSATOR COMPRISING FIBERS TO PRODUCE A RESILIENT LOAD, now U.S.Patent Application Publication No. 2012/0241500;

U.S. application Ser. No. 13/433,148, entitled TISSUE THICKNESSCOMPENSATOR COMPRISING STRUCTURE TO PRODUCE A RESILIENT LOAD, now U.S.Patent Application Publication No. 2012/0241501;

U.S. application Ser. No. 13/433,155, entitled TISSUE THICKNESSCOMPENSATOR COMPRISING RESILIENT MEMBERS, now U.S. Patent ApplicationPublication No. 2012/0241502;

U.S. application Ser. No. 13/433,163, entitled METHODS FOR FORMINGTISSUE THICKNESS COMPENSATOR ARRANGEMENTS FOR SURGICAL STAPLERS, nowU.S. Patent Application Publication No. 2012/0248169;

U.S. application Ser. No. 13/433,167, entitled TISSUE THICKNESSCOMPENSATORS, now U.S. Patent Application Publication No. 2012/0241503;

U.S. application Ser. No. 13/433,175, entitled LAYERED TISSUE THICKNESSCOMPENSATOR, now U.S. Patent Application Publication No. 2012/0253298;

U.S. application Ser. No. 13/433,179, entitled TISSUE THICKNESSCOMPENSATORS FOR CIRCULAR SURGICAL STAPLERS, now U.S. Patent ApplicationPublication No. 2012/0241505;

U.S. application Ser. No. 13/433,115, entitled TISSUE THICKNESSCOMPENSATOR COMPRISING CAPSULES DEFINING A LOW PRESSURE ENVIRONMENT, nowU.S. Patent Application Publication No. 2013/0236372;

U.S. application Ser. No. 13/433,118, entitled TISSUE THICKNESSCOMPENSATOR COMPRISED OF A PLURALITY OF MATERIALS, now U.S. PatentApplication Publication No. 2013/0256365;

U.S. application Ser. No. 13/433,135, entitled MOVABLE MEMBER FOR USEWITH A TISSUE THICKNESS COMPENSATOR, now U.S. Patent ApplicationPublication No. 2013/0256382;

U.S. application Ser. No. 13/433,129, entitled TISSUE THICKNESSCOMPENSATOR COMPRISING A PLURALITY OF MEDICAMENTS, now U.S. PatentApplication Publication No. 2013/0256367;

U.S. application Ser. No. 13/433,140, entitled TISSUE THICKNESSCOMPENSATOR AND METHOD FOR MAKING THE SAME, now U.S. Patent ApplicationPublication No. 2013/0256368;

U.S. application Ser. No. 13/433,147, entitled TISSUE THICKNESSCOMPENSATOR COMPRISING CHANNELS, now U.S. Patent Application PublicationNo. 2013/0256369;

U.S. application Ser. No. 13/433,126, entitled TISSUE THICKNESSCOMPENSATOR COMPRISING TISSUE INGROWTH FEATURES, now U.S. PatentApplication Publication No. 2013/0256366; and

U.S. application Ser. No. 13/433,132, entitled DEVICES AND METHODS FORATTACHING TISSUE THICKNESS COMPENSATING MATERIALS TO SURGICAL STAPLINGINSTRUMENTS, now U.S. Patent Application Publication No. 2013/0256373.

Certain exemplary embodiments will now be described to provide anoverall understanding of the principles of the structure, function,manufacture, and use of the devices and methods disclosed herein. One ormore examples of these embodiments are illustrated in the accompanyingdrawings. Those of ordinary skill in the art will understand that thedevices and methods specifically described herein and illustrated in theaccompanying drawings are non-limiting exemplary embodiments and thatthe scope of the various embodiments of the present invention is definedsolely by the claims. The features illustrated or described inconnection with one exemplary embodiment may be combined with thefeatures of other embodiments. Such modifications and variations areintended to be included within the scope of the present invention.

Reference throughout the specification to “various embodiments,” “someembodiments,” “one embodiment,” or “an embodiment”, or the like, meansthat a particular feature, structure, or characteristic described inconnection with the embodiment is included in at least one embodiment.Thus, appearances of the phrases “in various embodiments,” “in someembodiments,” “in one embodiment”, or “in an embodiment”, or the like,in places throughout the specification are not necessarily all referringto the same embodiment. Furthermore, the particular features,structures, or characteristics may be combined in any suitable manner inone or more embodiments. Thus, the particular features, structures, orcharacteristics illustrated or described in connection with oneembodiment may be combined, in whole or in part, with the featuresstructures, or characteristics of one or more other embodiments withoutlimitation. Such modifications and variations are intended to beincluded within the scope of the present invention.

The terms “proximal” and “distal” are used herein with reference to aclinician manipulating the handle portion of the surgical instrument.The term “proximal” referring to the portion closest to the clinicianand the term “distal” referring to the portion located away from theclinician. It will be further appreciated that, for convenience andclarity, spatial terms such as “vertical”, “horizontal”, “up”, and“down” may be used herein with respect to the drawings. However,surgical instruments are used in many orientations and positions, andthese terms are not intended to be limiting and/or absolute.

Various exemplary devices and methods are provided for performinglaparoscopic and minimally invasive surgical procedures. However, theperson of ordinary skill in the art will readily appreciate that thevarious methods and devices disclosed herein can be used in numeroussurgical procedures and applications including, for example, inconnection with open surgical procedures. As the present DetailedDescription proceeds, those of ordinary skill in the art will furtherappreciate that the various instruments disclosed herein can be insertedinto a body in any way, such as through a natural orifice, through anincision or puncture hole formed in tissue, etc. The working portions orend effector portions of the instruments can be inserted directly into apatient's body or can be inserted through an access device that has aworking channel through which the end effector and elongated shaft of asurgical instrument can be advanced.

Turning to the Drawings wherein like numerals denote like componentsthroughout the several views, FIG. 1 depicts a surgical instrument 10that is capable of practicing several unique benefits. The surgicalstapling instrument 10 is designed to manipulate and/or actuate variousforms and sizes of end effectors 12 that are operably attached thereto.In the embodiment depicted in FIGS. 1-1E, for example, the end effector12 includes an elongated channel 14 that forms a lower jaw 13 of the endeffector 12. The elongated channel 14 is configured to support an“implantable” staple cartridge 30 and also movably support an anvil 20that functions as an upper jaw 15 of the end effector 12.

In various embodiments, the elongated channel 14 may be fabricated from,for example, 300 & 400 Series, 17-4 & 17-7 stainless steel, titanium,etc. and be formed with spaced side walls 16. The anvil 20 may befabricated from, for example, 300 & 400 Series, 17-4 & 17-7 stainlesssteel, titanium, etc. and have a staple forming undersurface, generallylabeled as 22 that has a plurality of staple forming pockets 23 formedtherein. See FIGS. 1B-1E. In addition, the anvil 20 has a bifurcatedramp assembly 24 that protrudes proximally therefrom. An anvil pin 26protrudes from each lateral side of the ramp assembly 24 to be receivedwithin a corresponding slot or opening 18 in the side walls 16 of theelongated channel 14 to facilitate its movable or pivotable attachmentthereto.

Various forms of implantable staple cartridges may be employed with thevarious embodiments of the surgical instruments disclosed herein.Specific staple cartridge configurations and constructions will bediscussed in further detail below. However, in the embodiment depictedin FIG. 1A, an implantable staple cartridge 30 is shown. In at least oneembodiment, the staple cartridge 30 has a body portion 31 that consistsof a compressible hemostat material such as, for example, oxidizedregenerated cellulose (“ORC”) or a bio-absorbable foam in which lines ofunformed metal staples 32 are supported. In at least some embodiments,in order to prevent the staple from being affected and the hemostatmaterial from being activated during the introduction and positioningprocess, the entire cartridge may be coated or wrapped in abiodegradable film 38 such as a polydioxanon film sold under thetrademark PDS® or with a Polyglycerol sebacate (PGS) film or otherbiodegradable films formed from PGA (Polyglycolic acid, marketed underthe trade mark Vicryl), PCL (Polycaprolactone), PLA or PLLA (Polylacticacid), PHA (polyhydroxyalkanoate), PGCL (poliglecaprone 25, sold underthe trademark Monocryl) or a composite of PGA, PCL, PLA, PDS that wouldbe impermeable until ruptured. The body 31 of staple cartridge 30 issized to be removably supported within the elongated channel 14 as shownsuch that each staple 32 therein is aligned with corresponding stapleforming pockets 23 in the anvil when the anvil 20 is driven into formingcontact with the staple cartridge 30.

In use, once the end effector 12 has been positioned adjacent the targettissue, the end effector 12 is manipulated to capture or clamp thetarget tissue between an upper face 36 of the staple cartridge 30 andthe staple forming surface 22 of the anvil 20. The staples 32 are formedby moving the anvil 20 in a path that is substantially parallel to theelongated channel 14 to bring the staple forming surface 22 and, moreparticularly, the staple forming pockets 23 therein into substantiallysimultaneous contact with the upper face 36 of the staple cartridge 30.As the anvil 20 continues to move into the staple cartridge 30, the legs34 of the staples 32 contact a corresponding staple forming pocket 23 inanvil 20 which serves to bend the staple legs 34 over to form thestaples 32 into a “B shape”. Further movement of the anvil 20 toward theelongated channel 14 will further compress and form the staples 32 to adesired final formed height “FF”.

The above-described staple forming process is generally depicted inFIGS. 1B-1E. For example, FIG. 1B illustrates the end effector 12 withtarget tissue “T” between the anvil 20 and the upper face 36 of theimplantable staple cartridge 30. FIG. 1C illustrates the initialclamping position of the anvil 20 wherein the anvil has 20 been closedonto the target tissue “T” to clamp the target tissue “T” between theanvil 20 and the upper face 36 of the staple cartridge 30. FIG. 1Dillustrates the initial staple formation wherein the anvil 20 hasstarted to compress the staple cartridge 30 such that the legs 34 of thestaples 32 are starting to be formed by the staple forming pockets 23 inthe anvil 20. FIG. 1E illustrates the staple 32 in its final formedcondition through the target tissue “T” with the anvil 20 removed forclarity purposes. Once the staples 32 have been formed and fastened tothe target tissue “T”, the surgeon will move the anvil 20 to the openposition to enable the cartridge body 31 and the staples 32 to remainaffixed to the target tissue while the end effector 12 is beingwithdrawn from the patient. The end effector 12 forms all of the staplessimultaneously as the two jaws 13, 15 are clamped together. Theremaining “crushed” body materials 31 act as both a hemostat (the ORC)and a staple line reinforcement (PGA, PDS or any of the other filmcompositions mentioned above 38). Also, since the staples 32 never haveto leave the cartridge body 31 during forming, the likelihood of thestaples 32 being malformed during forming is minimized. As used hereinthe term “implantable” means that, in addition to the staples, thecartridge body materials that support the staples will also remain inthe patient and may eventually be absorbed by the patient's body. Suchimplantable staple cartridges are distinguishable from prior cartridgearrangements that remain positioned within the end effector in theirentirety after they have been fired.

In various implementations, the end effector 12 is configured to becoupled to an elongated shaft assembly 40 that protrudes from a handleassembly 100. The end effector 12 (when closed) and the elongated shaftassembly 40 may have similar cross-sectional shapes and be sized tooperably pass through a trocar tube or working channel in another formof access instrument. As used herein, the term “operably pass” meansthat the end effector and at least a portion of the elongated shaftassembly may be inserted through or passed through the channel or tubeopening and can be manipulated therein as needed to complete thesurgical stapling procedure. In some embodiments, when in a closedposition, the jaws 13 and 15 of the end effector 12 may provide the endeffector with a roughly circular cross-sectional shape that facilitatesits passage through a circular passage/opening. However, the endeffectors of various embodiments of the present invention, as well asthe elongated shaft assembly embodiments, could conceivably be providedwith other cross-sectional shapes that could otherwise pass throughaccess passages and openings that have non-circular cross-sectionalshapes. Thus, an overall size of a cross-section of a closed endeffector will be related to the size of the passage or opening throughwhich it is intended to pass. Thus, one end effector for example, may bereferred to as a “5 mm” end effector which means it can operably passthrough an opening that is at least approximately 5 mm in diameter.

In various embodiments, the elongated shaft assembly 40 may have anouter diameter that is substantially the same as the outer diameter ofthe end effector 12 when in a closed position. For example, a 5 mm endeffector may be coupled to an elongated shaft assembly 40 that has 5 mmcross-sectional diameter. However, as the present Detailed Descriptionproceeds, it will become apparent that various embodiments of thepresent may be effectively used in connection with different sizes ofend effectors. For example, a 10 mm end effector may be attached to anelongated shaft that has a 5 mm cross-sectional diameter. Conversely,for those applications wherein a 10 mm or larger access opening orpassage is provided, the elongated shaft assembly 40 may have a 10 mm(or larger) cross-sectional diameter, but may also be able to actuate a5 mm or 10 mm end effector. Accordingly, the outer shaft 40 may have anouter diameter that is the same as or is different from the outerdiameter of a closed end effector 12 attached thereto.

As depicted, the elongated shaft assembly 40 extends distally from thehandle assembly 100 in a generally straight line to define alongitudinal axis A-A. In various embodiments, for example, theelongated shaft assembly 40 may be approximately 9-16 inches (229-406mm) long. However, the elongated shaft assembly 40 may be provided inother lengths and, in other embodiments, may have joints therein or beotherwise configured to facilitate articulation of the end effector 12relative to other portions of the shaft or handle assembly as will bediscussed in further detail below. In various embodiments, the elongatedshaft assembly 40 includes a spine member 50 that extends from thehandle assembly 100 to the end effector 12. The proximal end of theelongated channel 14 of the end effector 12 has a pair of retentiontrunnions 17 protruding therefrom that are sized to be received withincorresponding trunnion openings or cradles 52 that are provided in adistal end of the spine member 50 to enable the end effector 12 to beremovably coupled the elongated shaft assembly 40. The spine member 50may be fabricated from, for example, 6061 or 7075 aluminum, stainlesssteel, titanium, etc.

In various embodiments, the handle assembly 100 comprises a pistolgrip-type housing that may be fabricated in two or more pieces forassembly purposes. For example, the handle assembly 100 as showncomprises a right hand case member 102 and a left hand case member (notillustrated) that are molded or otherwise fabricated from a polymer orplastic material and are designed to mate together. Such case membersmay be attached together by snap features, pegs and sockets molded orotherwise formed therein and/or by adhesive, screws, etc. The spinemember 50 has a proximal end 54 that has a flange 56 formed thereon. Theflange 56 is configured to be rotatably supported within a groove 106formed by mating ribs 108 that protrude inwardly from each of the casemembers 102, 104. Such arrangement facilitates the attachment of thespine member 50 to the handle assembly 100 while enabling the spinemember 50 to be rotated relative to the handle assembly 100 about thelongitudinal axis A-A in a 360° path.

As can be further seen in FIG. 1, the spine member 50 passes through andis supported by a mounting bushing 60 that is rotatably affixed to thehandle assembly 100. The mounting bushing 60 has a proximal flange 62and a distal flange 64 that define a rotational groove 65 that isconfigured to rotatably receive a nose portion 101 of the handleassembly 100 therebetween. Such arrangement enables the mounting bushing60 to rotate about longitudinal axis A-A relative to the handle assembly100. The spine member 50 is non-rotatably pinned to the mounting bushing60 by a spine pin 66. In addition, a rotation knob 70 is attached to themounting bushing 60. In one embodiment, for example, the rotation knob70 has a hollow mounting flange portion 72 that is sized to receive aportion of the mounting bushing 60 therein. In various embodiments, therotation knob 70 may be fabricated from, for example, glass or carbonfilled Nylon, polycarbonate, Ultem®, etc. and is affixed to the mountingbushing 60 by the spine pin 66 as well. In addition, an inwardlyprotruding retention flange 74 is formed on the mounting flange portion72 and is configured to extend into a radial groove 68 formed in themounting bushing 60. Thus, the surgeon may rotate the spine member 50(and the end effector 12 attached thereto) about longitudinal axis A-Ain a 360° path by grasping the rotation knob 70 and rotating it relativeto the handle assembly 100.

In various embodiments, the anvil 20 is retained in an open position byan anvil spring 21 and/or another biasing arrangement. The anvil 20 isselectively movable from the open position to various closed or clampingand firing positions by a firing system, generally designated as 109.The firing system 109 includes a “firing member” 110 which, in variousembodiments, comprises a hollow firing tube 110. The hollow firing tube110 is axially movable on the spine member 50 and thus forms the outerportion of the elongated shaft assembly 40. The firing tube 110 may befabricated from a polymer or other suitable material and have a proximalend that is attached to a firing yoke 114 of the firing system 109. Invarious embodiments for example, the firing yoke 114 may be over-moldedto the proximal end of the firing tube 110. However, other fastenerarrangements may be employed.

As can be seen in FIG. 1, the firing yoke 114 may be rotatably supportedwithin a support collar 120 that is configured to move axially withinthe handle assembly 100. In various embodiments, the support collar 120has a pair of laterally extending fins that are sized to be slidablyreceived within fin slots formed in the right and left hand casemembers. Thus, the support collar 120 may slide axially within thehandle housing 100 while enabling the firing yoke 114 and firing tube110 to rotate relative thereto about the longitudinal axis A-A. Invarious embodiments, a longitudinal slot is provided through the firingtube 110 to enable the spine pin 66 to extend therethrough into thespine member 50 while facilitating the axial travel of the firing tube110 on the spine member 50.

The firing system 109 further comprises a firing trigger 130 whichserves to control the axial travel of the firing tube 110 on the spinemember 50. See FIG. 1. Such axial movement in the distal direction ofthe firing tube 110 into firing interaction with the anvil 20 isreferred to herein as “firing motion”. As can be seen in FIG. 1, thefiring trigger 130 is movably or pivotally coupled to the handleassembly 100 by a pivot pin 132. A torsion spring 135 is employed tobias the firing trigger 130 away from the pistol grip portion 107 of thehandle assembly 100 to an un-actuated “open” or starting position. Ascan be seen in FIG. 1, the firing trigger 130 has an upper portion 134that is movably attached to (pinned) firing links 136 that are movablyattached to (pinned) the support collar 120. Thus, movement of thefiring trigger 130 from the starting position (FIG. 1) toward an endingposition adjacent the pistol grip portion 107 of the handle assembly 100will cause the firing yoke 114 and the firing tube 110 to move in thedistal direction “DD”. Movement of the firing trigger 130 away from thepistol grip portion 107 of the handle assembly 100 (under the bias ofthe torsion spring 135) will cause the firing yoke 114 and firing tube110 to move in the proximal direction “PD” on the spine member 50.

Various embodiments of the present invention may be employed withdifferent sizes and configurations of implantable staple cartridges. Forexample, the surgical instrument 10, when used in connection with afirst firing adapter 140, may be used with a 5 mm end effector 12 thatis approximately 20 mm long (or in other lengths) which supports animplantable staple cartridge 30. Such end effector size may beparticularly well-suited, for example, to complete relatively finedissection and vascular transactions. However, as will be discussed infurther detail below, the surgical instrument 10 may also be employed,for example, in connection with other sizes of end effectors and staplecartridges by replacing the first firing adapter 140 with a secondfiring adapter. In still other embodiments, the elongated shaft assembly40 may configured to be attached to only one form or size of endeffector.

One method of removably coupling the end effector 12 to the spine member50 will now be explained. The coupling process is commenced by insertingthe retention trunnions 17 on the elongated channel 14 into the trunnioncradles 52 in the spine member 50. Thereafter, the surgeon advances thefiring trigger 130 toward the pistol grip 107 of the housing assembly100 to distally advance the firing tube 110 and the first firing adapter140 over a proximal end portion 47 of the elongated channel 14 tothereby retain the trunnions 17 in their respective cradles 52. Suchposition of the first firing adapter 140 over the trunnions 17 isreferred to herein as the “coupled position”. Various embodiments of thepresent invention may also have an end effector locking assembly forlocking the firing trigger 130 in position after an end effector 12 hasbeen attached to the spine member 50.

More specifically, one embodiment of the end effector locking assembly160 includes a retention pin 162 that is movably supported in the upperportion 134 of the firing trigger 130. As discussed above, the firingtube 110 must initially be advanced distally to the coupled positionwherein the first firing adapter 140 retains the retention trunnions 17of the end effector 12 in the trunnion cradles 52 in the spine member50. The surgeon advances the firing adapter 140 distally to the coupledposition by pulling the firing trigger 130 from the starting positiontoward the pistol grip 107. As the firing trigger 130 is initiallyactuated, the retention pin 162 is moved distally until the firing tube110 has advanced the first firing adapter 140 to the coupled position atwhich point the retention pin 162 is biased into a locking cavity 164formed in the case member. In various embodiments, when the retentionpin 162 enters into the locking cavity 164, the pin 162 may make anaudible “click” or other sound, as well as provide a tactile indicationto the surgeon that the end effector 12 has been “locked” onto the spinemember 50. In addition, the surgeon cannot inadvertently continue toactuate the firing trigger 130 to start to form staples 32 in the endeffector 12 without intentionally biasing the retention pin 162 out ofthe locking cavity 164. Similarly, if the surgeon releases the firingtrigger 130 when in the coupled position, it is retained in thatposition by the retention pin 162 to prevent the firing trigger 130 fromreturning to the starting position and thereby releasing the endeffector 12 from the spine member 50.

Various embodiments of the present invention may further include afiring system lock button 137 that is pivotally attached to the handleassembly 100. In one form, the firing system lock button 137 has a latch138 formed on a distal end thereof that is oriented to engage the firingyoke 114 when the firing release button is in a first latching position.As can be seen in FIG. 1, a latch spring 139 serves to bias the firingsystem lock button 137 to the first latching position. In variouscircumstances, the latch 138 serves to engage the firing yoke 114 at apoint where the position of the firing yoke 114 on the spine member 50corresponds to a point wherein the first firing adapter 140 is about todistally advance up the clamping ramp 28 on the anvil 20. It will beunderstood that, as the first firing adapter 140 advances axially up theclamping ramp 28, the anvil 20 will move in a path such that its stapleforming surface portion 22 is substantially parallel to the upper face36 of the staple cartridge 30.

After the end effector 12 has been coupled to the spine member 50, thestaple forming process is commenced by first depressing the firingsystem lock button 137 to enable the firing yoke 114 to be further moveddistally on the spine member 50 and ultimately compress the anvil 20into the staple cartridge 30. After depressing the firing system lockbutton 137, the surgeon continues to actuate the firing trigger 130towards the pistol grip 107 thereby driving the first staple collar 140up the corresponding staple forming ramp 29 to force the anvil 20 intoforming contact with the staples 32 in the staple cartridge 30. Thefiring system lock button 137 prevents the inadvertent forming of thestaples 32 until the surgeon is ready to start that process. In thisembodiment, the surgeon must depress the firing system lock button 137before the firing trigger 130 may be further actuated to begin thestaple forming process.

The surgical instrument 10 may be solely used as a tissue staplingdevice if so desired. However, various embodiments of the presentinvention may also include a tissue cutting system, generally designatedas 170. In at least one form, the tissue cutting system 170 comprises aknife member 172 that may be selectively advanced from an un-actuatedposition adjacent the proximal end of the end effector 12 to an actuatedposition by actuating a knife advancement trigger 200. The knife member172 is movably supported within the spine member 50 and is attached orotherwise protrudes from a knife rod 180. The knife member 172 may befabricated from, for example, 420 or 440 stainless steel with a hardnessof greater than 38 HRC (Rockwell Hardness C-scale) and have a tissuecutting edge 176 formed on the distal end 174 thereof and be configuredto slidably extend through a slot in the anvil 20 and a centrallydisposed slot 33 in the staple cartridge 30 to cut through tissue thatis clamped in the end effector 12. In various embodiments, the knife rod180 extends through the spine member 50 and has a proximal end portionwhich drivingly interfaces with a knife transmission that is operablyattached to the knife advance trigger 200. In various embodiments, theknife advance trigger 200 is attached to pivot pin 132 such that it maybe pivoted or otherwise actuated without actuating the firing trigger130. In various embodiments, a first knife gear 192 is also attached tothe pivot pin 132 such that actuation of the knife advance trigger 200also pivots the first knife gear 192. A firing return spring 202 isattached between the first knife gear 192 and the handle housing 100 tobias the knife advancement trigger 200 to a starting or un-actuatedposition.

Various embodiments of the knife transmission also include a secondknife gear 194 that is rotatably supported on a second gear spindle andin meshing engagement with the first knife gear 192. The second knifegear 194 is in meshing engagement with a third knife gear 196 that issupported on a third gear spindle. Also supported on the third gearspindle 195 is a fourth knife gear 198. The fourth knife gear 198 isadapted to drivingly engage a series of annular gear teeth or rings on aproximal end of the knife rod 180. Thus, such arrangement enables thefourth knife gear 198 to axially drive the knife rod 180 in the distaldirection “DD” or proximal direction “PD” while enabling the firing rod180 to rotate about longitudinal axis A-A with respect to the fourthknife gear 198. Accordingly, the surgeon may axially advance the firingrod 180 and ultimately the knife member 172 distally by pulling theknife advancement trigger 200 towards the pistol grip 107 of the handleassembly 100.

Various embodiments of the present invention further include a knifelockout system 210 that prevents the advancement of the knife member 172unless the firing trigger 130 has been pulled to the fully firedposition. Such feature will therefore prevent the activation of theknife advancement system 170 unless the staples have first been fired orformed into the tissue. As can be seen in FIG. 1, variousimplementations of the knife lockout system 210 comprise a knife lockoutbar 211 that is pivotally supported within the pistol grip portion 107of the handle assembly 100. The knife lockout bar 211 has an activationend 212 that is adapted to be engaged by the firing trigger 130 when thefiring trigger 130 is in the fully fired position. In addition, theknife lockout bar 211 has a retaining hook 214 on its other end that isadapted to hookingly engage a latch rod 216 on the first cut gear 192. Aknife lock spring 218 is employed to bias the knife lockout bar 211 to a“locked” position wherein the retaining hook 214 is retained inengagement with the latch rod 216 to thereby prevent actuation of theknife advancement trigger 200 unless the firing trigger 130 is in thefully fired position.

After the staples have been “fired” (formed) into the target tissue, thesurgeon may depress the firing trigger release button 167 to enable thefiring trigger 130 to return to the starting position under the bias ofthe torsion spring 135 which enables the anvil 20 to be biased to anopen position under the bias of spring 21. When in the open position,the surgeon may withdraw the end effector 12 leaving the implantablestaple cartridge 30 and staples 32 behind. In applications wherein theend effector was inserted through a passage, working channel, etc. thesurgeon will return the anvil 20 to the closed position by activatingthe firing trigger 130 to enable the end effector 12 to be withdrawn outthrough the passage or working channel. If, however, the surgeon desiresto cut the target tissue after firing the staples, the surgeon activatesthe knife advancement trigger 200 in the above-described manner to drivethe knife bar 172 through the target tissue to the end of the endeffector. Thereafter, the surgeon may release the knife advancementtrigger 200 to enable the firing return spring 202 to cause the firingtransmission to return the knife bar 172 to the starting (un-actuated)position. Once the knife bar 172 has been returned to the startingposition, the surgeon may open the end effector jaws 13, 15 to releasethe implantable cartridge 30 within the patient and then withdraw theend effector 12 from the patient. Thus, such surgical instrumentsfacilitate the use of small implantable staple cartridges that may beinserted through relatively smaller working channels and passages, whileproviding the surgeon with the option to fire the staples withoutcutting tissue or if desired to also cut tissue after the staples havebeen fired.

Various unique and novel embodiments of the present invention employ acompressible staple cartridge that supports staples in a substantiallystationary position for forming contact by the anvil. In variousembodiments, the anvil is driven into the unformed staples wherein, inat least one such embodiment, the degree of staple formation attained isdependent upon how far the anvil is driven into the staples. Such anarrangement provides the surgeon with the ability to adjust the amountof forming or firing pressure applied to the staples and thereby alterthe final formed height of the staples. In other various embodiments ofthe present invention, surgical stapling arrangements can employ stapledriving elements which can lift the staples toward the anvil. Suchembodiments are described in greater detail further below.

In various embodiments, with regard to the embodiments described indetail above, the amount of firing motion that is applied to the movableanvil is dependent upon the degree of actuation of the firing trigger.For example, if the surgeon desires to attain only partially formedstaples, then the firing trigger is only partially depressed inwardtowards the pistol grip 107. To attain more staple formation, thesurgeon simply compresses the firing trigger further which results inthe anvil being further driven into forming contact with the staples. Asused herein, the term “forming contact” means that the staple formingsurface or staple forming pockets have contacted the ends of the staplelegs and have started to form or bend the legs over into a formedposition. The degree of staple formation refers to how far the staplelegs have been folded over and ultimately relates to the forming heightof the staple as referenced above. Those of ordinary skill in the artwill further understand that, because the anvil 20 moves in asubstantially parallel relationship with respect to the staple cartridgeas the firing motions are applied thereto, the staples are formedsubstantially simultaneously with substantially the same formed heights.

FIGS. 2 and 3 illustrate an alternative end effector 12″ that is similarto the end effector 12′ described above, except with the followingdifferences that are configured to accommodate a knife bar 172′. Theknife bar 172′ is coupled to or protrudes from a knife rod 180 and isotherwise operated in the above described manner with respect to theknife bar 172. However, in this embodiment, the knife bar 172′ is longenough to traverse the entire length of the end effector 12″ andtherefore, a separate distal knife member is not employed in the endeffector 12″. The knife bar 172′ has an upper transverse member 173′ anda lower transverse member 175′ formed thereon. The upper transversemember 173′ is oriented to slidably transverse a corresponding elongatedslot 250 in anvil 20″ and the lower transverse member 175′ is orientedto traverse an elongated slot 252 in the elongated channel 14″ of theend effector 12″. A disengagement slot (not shown) is also provided inthe anvil 20″ such that when the knife bar 172′ has been driven to anending position within end effector 12″, the upper transverse member173′ drops through the corresponding slot to enable the anvil 20″ tomove to the open position to disengage the stapled and cut tissue. Theanvil 20″ may be otherwise identical to anvil 20 described above and theelongated channel 14″ may be otherwise identical to elongated channel 14described above.

In these embodiments, the anvil 20″ is biased to a fully open position(FIG. 2) by a spring or other opening arrangement (not shown). The anvil20″ is moved between the open and fully clamped positions by the axialtravel of the firing adapter 150 in the manner described above. Once thefiring adapter 150 has been advanced to the fully clamped position (FIG.3), the surgeon may then advance the knife bar 172″ distally in themanner described above. If the surgeon desires to use the end effectoras a grasping device to manipulate tissue, the firing adapter may bemoved proximally to allow the anvil 20″ to move away from the elongatedchannel 14″ as represented in FIG. 4 in broken lines. In thisembodiment, as the knife bar 172″ moves distally, the upper transversemember 173′ and the lower transverse member 175′ draw the anvil 20″ andelongated channel 14″ together to achieve the desired staple formationas the knife bar 172″ is advanced distally through the end effector 12″.See FIG. 5. Thus, in this embodiment, staple formation occurssimultaneously with tissue cutting, but the staples themselves may besequentially formed as the knife bar 172″ is driven distally.

The unique and novel features of the various surgical staple cartridgesand the surgical instruments of the present invention enable the staplesin those cartridges to be arranged in one or more linear or non-linearlines. A plurality of such staple lines may be provided on each side ofan elongated slot that is centrally disposed within the staple cartridgefor receiving the tissue cutting member therethrough. In onearrangement, for example, the staples in one line may be substantiallyparallel with the staples in adjacent line(s) of staples, but offsettherefrom. In still other embodiments, one or more lines of staples maybe non-linear in nature. That is, the base of at least one staple in aline of staples may extend along an axis that is substantiallytransverse to the bases of other staples in the same staple line. Forexample, the lines of staples on each side of the elongated slot mayhave a zigzag appearance.

In various embodiments, a staple cartridge can comprise a cartridge bodyand a plurality of staples stored within the cartridge body. In use, thestaple cartridge can be introduced into a surgical site and positionedon a side of the tissue being treated. In addition, a staple-forminganvil can be positioned on the opposite side of the tissue. In variousembodiments, the anvil can be carried by a first jaw and the staplecartridge can be carried by a second jaw, wherein the first jaw and/orthe second jaw can be moved toward the other. Once the staple cartridgeand the anvil have been positioned relative to the tissue, the staplescan be ejected from the staple cartridge body such that the staples canpierce the tissue and contact the staple-forming anvil. Once the stapleshave been deployed from the staple cartridge body, the staple cartridgebody can then be removed from the surgical site. In various embodimentsdisclosed herein, a staple cartridge, or at least a portion of a staplecartridge, can be implanted with the staples. In at least one suchembodiment, as described in greater detail further below, a staplecartridge can comprise a cartridge body which can be compressed,crushed, and/or collapsed by the anvil when the anvil is moved from anopen position into a closed position. When the cartridge body iscompressed, crushed, and/or collapsed, the staples positioned within thecartridge body can be deformed by the anvil. Alternatively, the jawsupporting the staple cartridge can be moved toward the anvil into aclosed position. In either event, in various embodiments, the staplescan be deformed while they are at least partially positioned within thecartridge body. In certain embodiments, the staples may not be ejectedfrom the staple cartridge while, in some embodiments, the staples can beejected from the staple cartridge along with a portion of the cartridgebody.

Referring now to FIGS. 6A-6D, a compressible staple cartridge, such asstaple cartridge 1000, for example, can comprise a compressible,implantable cartridge body 1010 and, in addition, a plurality of staples1020 positioned in the compressible cartridge body 1010, although onlyone staple 1020 is depicted in FIGS. 6A-6D. FIG. 6A illustrates thestaple cartridge 1000 supported by a staple cartridge support, or staplecartridge channel, 1030, wherein the staple cartridge 1000 isillustrated in an uncompressed condition. In such an uncompressedcondition, the anvil 1040 may or may not be in contact with the tissueT. In use, the anvil 1040 can be moved from an open position intocontact with the tissue T as illustrated in FIG. 6B and position thetissue T against the cartridge body 1010. Even though the anvil 1040 canposition the tissue T against a tissue-contacting surface 1019 of staplecartridge body 1010, referring again to FIG. 6B, the staple cartridgebody 1010 may be subjected to little, if any, compressive force orpressure at such point and the staples 1020 may remain in an unformed,or unfired, condition. As illustrated in FIGS. 6A and 6B, the staplecartridge body 1010 can comprise one or more layers and the staple legs1021 of staples 1020 can extend upwardly through these layers. Invarious embodiments, the cartridge body 1010 can comprise a first layer1011, a second layer 1012, a third layer 1013, wherein the second layer1012 can be positioned intermediate the first layer 1011 and the thirdlayer 1013, and a fourth layer 1014, wherein the third layer 1013 can bepositioned intermediate the second layer 1012 and the fourth layer 1014.In at least one embodiment, the bases 1022 of the staples 1020 can bepositioned within cavities 1015 in the fourth layer 1014 and the staplelegs 1021 can extend upwardly from the bases 1022 and through the fourthlayer 1014, the third layer 1013, and the second layer 1012, forexample. In various embodiments, each deformable leg 1021 can comprise atip, such as sharp tip 1023, for example, which can be positioned in thesecond layer 1012, for example, when the staple cartridge 1000 is in anuncompressed condition. In at least one such embodiment, the tips 1023may not extend into and/or through the first layer 1011, wherein, in atleast one embodiment, the tips 1023 may not protrude through thetissue-contacting surface 1019 when the staple cartridge 1000 is in anuncompressed condition. In certain other embodiments, the sharp tips1023 may be positioned in the third layer 1013, and/or any othersuitable layer, when the staple cartridge is in an uncompressedcondition. In various alternative embodiments, a cartridge body of astaple cartridge may have any suitable number of layers such as lessthan four layers or more than four layers, for example.

In various embodiments, as described in greater detail below, the firstlayer 1011 can be comprised of a buttress material and/or plasticmaterial, such as polydioxanone (PDS) and/or polyglycolic acid (PGA),for example, and the second layer 1012 can be comprised of abioabsorbable foam material and/or a compressible haemostatic material,such as oxidized regenerated cellulose (ORC), for example. In variousembodiments, one or more of the first layer 1011, the second layer 1012,the third layer 1013, and the fourth layer 1014 may hold the staples1020 within the staple cartridge body 1010 and, in addition, maintainthe staples 1020 in alignment with one another. In various embodiments,the third layer 1013 can be comprised of a buttress material, or afairly incompressible or inelastic material, which can be configured tohold the staple legs 1021 of the staples 1020 in position relative toone another. Furthermore, the second layer 1012 and the fourth layer1014, which are positioned on opposite sides of the third layer 1013,can stabilize, or reduce the movement of, the staples 1020 even thoughthe second layer 1012 and the fourth layer 1014 can be comprised of acompressible foam or elastic material. In certain embodiments, thestaple tips 1023 of the staple legs 1021 can be at least partiallyembedded in the first layer 1011. In at least one such embodiment, thefirst layer 1011 and the third layer 1013 can be configured toco-operatively and firmly hold the staple legs 1021 in position. In atleast one embodiment, the first layer 1011 and the third layer 1013 caneach be comprised of a sheet of bioabsorbable plastic, such aspolyglycolic acid (PGA) which is marketed under the trade name Vicryl,polylactic acid (PLA or PLLA), polydioxanone (PDS), polyhydroxyalkanoate(PHA), poliglecaprone 25 (PGCL) which is marketed under the trade nameMonocryl, polycaprolactone (PCL), and/or a composite of PGA, PLA, PDS,PHA, PGCL and/or PCL, for example, and the second layer 1012 and thefourth layer 1014 can each be comprised of at least one haemostaticmaterial or agent.

Although the first layer 1011 can be compressible, the second layer 1012can be substantially more compressible than the first layer 1011. Forexample, the second layer 1012 can be about twice as compressible, aboutthree times as compressible, about four times as compressible, aboutfive times as compressible, and/or about ten times as compressible, forexample, as the first layer 1011. Stated another way, the second layer1012 may compress about two times, about three times, about four times,about five times, and/or about ten times as much as first layer 1011,for a given force. In certain embodiments, the second layer 1012 can bebetween about twice as compressible and about ten times as compressible,for example, as the first layer 1011. In at least one embodiment, thesecond layer 1012 can comprise a plurality of air voids defined therein,wherein the amount and/or size of the air voids in the second layer 1012can be controlled in order to provide a desired compressibility of thesecond layer 1012. Similar to the above, although the third layer 1013can be compressible, the fourth layer 1014 can be substantially morecompressible than the third layer 1013. For example, the fourth layer1014 can be about twice as compressible, about three times ascompressible, about four times as compressible, about five times ascompressible, and/or about ten times as compressible, for example, asthe third layer 1013. Stated another way, the fourth layer 1014 maycompress about two times, about three times, about four times, aboutfive times, and/or about ten times as much as third layer 1013, for agiven force. In certain embodiments, the fourth layer 1014 can bebetween about twice as compressible and about ten times as compressible,for example, as the third layer 1013. In at least one embodiment, thefourth layer 1014 can comprise a plurality of air voids defined therein,wherein the amount and/or size of the air voids in the fourth layer 1014can be controlled in order to provide a desired compressibility of thefourth layer 1014. In various circumstances, the compressibility of acartridge body, or cartridge body layer, can be expressed in terms of acompression rate, i.e., a distance in which a layer is compressed for agiven amount of force. For example, a layer having a high compressionrate will compress a larger distance for a given amount of compressiveforce applied to the layer as compared to a layer having a lowercompression rate. This being said, the second layer 1012 can have ahigher compression rate than the first layer 1011 and, similarly, thefourth layer 1014 can have a higher compression rate than the thirdlayer 1013. In various embodiments, the second layer 1012 and the fourthlayer 1014 can be comprised of the same material and can comprise thesame compression rate. In various embodiments, the second layer 1012 andthe fourth layer 1014 can be comprised of materials having differentcompression rates. Similarly, the first layer 1011 and the third layer1013 can be comprised of the same material and can comprise the samecompression rate. In certain embodiments, the first layer 1011 and thethird layer 1013 can be comprised of materials having differentcompression rates.

As the anvil 1040 is moved toward its closed position, the anvil 1040can contact tissue T and apply a compressive force to the tissue T andthe staple cartridge 1000, as illustrated in FIG. 6C. In suchcircumstances, the anvil 1040 can push the top surface, ortissue-contacting surface 1019, of the cartridge body 1010 downwardlytoward the staple cartridge support 1030. In various embodiments, thestaple cartridge support 1030 can comprise a cartridge support surface1031 which can be configured to support the staple cartridge 1000 as thestaple cartridge 1000 is compressed between the cartridge supportsurface 1031 and the tissue-contacting surface 1041 of anvil 1040. Owingto the pressure applied by the anvil 1040, the cartridge body 1010 canbe compressed and the anvil 1040 can come into contact with the staples1020. More particularly, in various embodiments, the compression of thecartridge body 1010 and the downward movement of the tissue-contactingsurface 1019 can cause the tips 1023 of the staple legs 1021 to piercethe first layer 1011 of cartridge body 1010, pierce the tissue T, andenter into forming pockets 1042 in the anvil 1040. As the cartridge body1010 is further compressed by the anvil 1040, the tips 1023 can contactthe walls defining the forming pockets 1042 and, as a result, the legs1021 can be deformed or curled inwardly, for example, as illustrated inFIG. 6C. As the staple legs 1021 are being deformed, as also illustratedin FIG. 6C, the bases 1022 of the staples 1020 can be in contact with orsupported by the staple cartridge support 1030. In various embodiments,as described in greater detail below, the staple cartridge support 1030can comprise a plurality of support features, such as staple supportgrooves, slots, or troughs 1032, for example, which can be configured tosupport the staples 1020, or at least the bases 1022 of the staples1020, as the staples 1020 are being deformed. As also illustrated inFIG. 6C, the cavities 1015 in the fourth layer 1014 can collapse as aresult of the compressive force applied to the staple cartridge body1010. In addition to the cavities 1015, the staple cartridge body 1010can further comprise one or more voids, such as voids 1016, for example,which may or may not comprise a portion of a staple positioned therein,that can be configured to allow the cartridge body 1010 to collapse. Invarious embodiments, the cavities 1015 and/or the voids 1016 can beconfigured to collapse such that the walls defining the cavities and/orwalls deflect downwardly and contact the cartridge support surface 1031and/or contact a layer of the cartridge body 1010 positioned underneaththe cavities and/or voids.

Upon comparing FIG. 6B and FIG. 6C, it is evident that the second layer1012 and the fourth layer 1014 have been substantially compressed by thecompressive pressure applied by the anvil 1040. It may also be notedthat the first layer 1011 and the third layer 1013 have been compressedas well. As the anvil 1040 is moved into its closed position, the anvil1040 may continue to further compress the cartridge body 1010 by pushingthe tissue-contacting surface 1019 downwardly toward the staplecartridge support 1030. As the cartridge body 1010 is furthercompressed, the anvil 1040 can deform the staples 1020 into theircompletely-formed shape as illustrated in FIG. 6D. Referring to FIG. 6D,the legs 1021 of each staple 1020 can be deformed downwardly toward thebase 1022 of each staple 1020 in order to capture at least a portion ofthe tissue T, the first layer 1011, the second layer 1012, the thirdlayer 1013, and the fourth layer 1014 between the deformable legs 1021and the base 1022. Upon comparing FIGS. 6C and 6D, it is further evidentthat the second layer 1012 and the fourth layer 1014 have been furthersubstantially compressed by the compressive pressure applied by theanvil 1040. It may also be noted upon comparing FIGS. 6C and 6D that thefirst layer 1011 and the third layer 1013 have been further compressedas well. After the staples 1020 have been completely, or at leastsufficiently, formed, the anvil 1040 can be lifted away from the tissueT and the staple cartridge support 1030 can be moved away, and/ordetached from, the staple cartridge 1000. As depicted in FIG. 6D, and asa result of the above, the cartridge body 1010 can be implanted with thestaples 1020. In various circumstances, the implanted cartridge body1010 can support the tissue along the staple line. In somecircumstances, a haemostatic agent, and/or any other suitabletherapeutic medicament, contained within the implanted cartridge body1010 can treat the tissue over time. A haemostatic agent, as mentionedabove, can reduce the bleeding of the stapled and/or incised tissuewhile a bonding agent or tissue adhesive can provide strength to thetissue over time. The implanted cartridge body 1010 can be comprised ofmaterials such as ORC (oxidized regenerated cellulose), extracellularproteins such as collagen, polyglycolic acid (PGA) which is marketedunder the trade name Vicryl, polylactic acid (PLA or PLLA),polydioxanone (PDS), polyhydroxyalkanoate (PHA), poliglecaprone 25(PGCL) which is marketed under the trade name Monocryl, polycaprolactone(PCL), and/or a composite of PGA, PLA, PDS, PHA, PGCL and/or PCL, forexample. In certain circumstances, the cartridge body 1010 can comprisean antibiotic and/or anti-microbial material, such as colloidal silverand/or triclosan, for example, which can reduce the possibility ofinfection in the surgical site.

In various embodiments, the layers of the cartridge body 1010 can beconnected to one another. In at least one embodiment, the second layer1012 can be adhered to the first layer 1011, the third layer 1013 can beadhered to the second layer 1012, and the fourth layer 1014 can beadhered to the third layer 1013 utilizing at least one adhesive, such asfibrin and/or protein hydrogel, for example. In certain embodiments,although not illustrated, the layers of the cartridge body 1010 can beconnected together by interlocking mechanical features. In at least onesuch embodiment, the first layer 1011 and the second layer 1012 can eachcomprise corresponding interlocking features, such as a tongue andgroove arrangement and/or a dovetail joint arrangement, for example.Similarly, the second layer 1012 and the third layer 1013 can eachcomprise corresponding interlocking features while the third layer 1013and the fourth layer 1014 can each comprise corresponding interlockingfeatures. In certain embodiments, although not illustrated, the staplecartridge 1000 can comprise one or more rivets, for example, which canextend through one or more layers of the cartridge body 1010. In atleast one such embodiment, each rivet can comprise a first end, or head,positioned adjacent to the first layer 1011 and a second head positionedadjacent to the fourth layer 1014 which can be either assembled to orformed by a second end of the rivet. Owing to the compressible nature ofthe cartridge body 1010, in at least one embodiment, the rivets cancompress the cartridge body 1010 such that the heads of the rivets canbe recessed relative to the tissue-contacting surface 1019 and/or thebottom surface 1018 of the cartridge body 1010, for example. In at leastone such embodiment, the rivets can be comprised of a bioabsorbablematerial, such as polyglycolic acid (PGA) which is marketed under thetrade name Vicryl, polylactic acid (PLA or PLLA), polydioxanone (PDS),polyhydroxyalkanoate (PHA), poliglecaprone 25 (PGCL) which is marketedunder the trade name Monocryl, polycaprolactone (PCL), and/or acomposite of PGA, PLA, PDS, PHA, PGCL and/or PCL, for example. Incertain embodiments, the layers of the cartridge body 1010 may not beconnected to one another other than by the staples 1020 containedtherein. In at least one such embodiment, the frictional engagementbetween the staple legs 1021 and the cartridge body 1010, for example,can hold the layers of the cartridge body 1010 together and, once thestaples have been formed, the layers can be captured within the staples1020. In certain embodiments, at least a portion of the staple legs 1021can comprise a roughened surface or rough coating which can increase thefriction forces between the staples 1020 and the cartridge body 1010.

As described above, a surgical instrument can comprise a first jawincluding the staple cartridge support 1030 and a second jaw includingthe anvil 1040. In various embodiments, as described in greater detailfurther below, the staple cartridge 1000 can comprise one or moreretention features which can be configured to engage the staplecartridge support 1030 and, as a result, releasably retain the staplecartridge 1000 to the staple cartridge support 1030. In certainembodiments, the staple cartridge 1000 can be adhered to the staplecartridge support 1030 by at least one adhesive, such as fibrin and/orprotein hydrogel, for example. In use, in at least one circumstance,especially in laparoscopic and/or endoscopic surgery, the second jaw canbe moved into a closed position opposite the first jaw, for example,such that the first and second jaws can be inserted through a trocarinto a surgical site. In at least one such embodiment, the trocar candefine an approximately 5 mm aperture, or cannula, through which thefirst and second jaws can be inserted. In certain embodiments, thesecond jaw can be moved into a partially-closed position intermediatethe open position and the closed position which can allow the first andsecond jaws to be inserted through the trocar without deforming thestaples 1020 contained in the staple cartridge body 1010. In at leastone such embodiment, the anvil 1040 may not apply a compressive force tothe staple cartridge body 1010 when the second jaw is in itspartially-closed intermediate position while, in certain otherembodiments, the anvil 1040 can compress the staple cartridge body 1010when the second jaw is in its partially-closed intermediate position.Even though the anvil 1040 can compress the staple cartridge body 1010when it is in such an intermediate position, the anvil 1040 may notsufficiently compress the staple cartridge body 1010 such that the anvil1040 comes into contact with the staples 1020 and/or such that thestaples 1020 are deformed by the anvil 1040. Once the first and secondjaws have been inserted through the trocar into the surgical site, thesecond jaw can be opened once again and the anvil 1040 and the staplecartridge 1000 can be positioned relative to the targeted tissue asdescribed above.

In various embodiments, referring now to FIGS. 7A-7D, an end effector ofa surgical stapler can comprise an implantable staple cartridge 1100positioned intermediate an anvil 1140 and a staple cartridge support1130. Similar to the above, the anvil 1140 can comprise atissue-contacting surface 1141, the staple cartridge 1100 can comprise atissue-contacting surface 1119, and the staple cartridge support 1130can comprise a support surface 1131 which can be configured to supportthe staple cartridge 1100. Referring to FIG. 7A, the anvil 1140 can beutilized to position the tissue T against the tissue contacting surface1119 of staple cartridge 1100 without deforming the staple cartridge1100 and, when the anvil 1140 is in such a position, thetissue-contacting surface 1141 can be positioned a distance 1101 a awayfrom the staple cartridge support surface 1131 and the tissue-contactingsurface 1119 can be positioned a distance 1102 a away from the staplecartridge support surface 1131. Thereafter, as the anvil 1140 is movedtoward the staple cartridge support 1130, referring now to FIG. 7B, theanvil 1140 can push the top surface, or tissue-contacting surface 1119,of staple cartridge 1100 downwardly and compress the first layer 1111and the second layer 1112 of cartridge body 1110. As the layers 1111 and1112 are compressed, referring again to FIG. 7B, the second layer 1112can be crushed and the legs 1121 of staples 1120 can pierce the firstlayer 1111 and enter into the tissue T. In at least one such embodiment,the staples 1120 can be at least partially positioned within staplecavities, or voids, 1115 in the second layer 1112 and, when the secondlayer 1112 is compressed, the staple cavities 1115 can collapse and, asa result, allow the second layer 1112 to collapse around the staples1120. In various embodiments, the second layer 1112 can comprise coverportions 1116 which can extend over the staple cavities 1115 andenclose, or at least partially enclose, the staple cavities 1115. FIG.7B illustrates the cover portions 1116 being crushed downwardly into thestaple cavities 1115. In certain embodiments, the second layer 1112 cancomprise one or more weakened portions which can facilitate the collapseof the second layer 1112. In various embodiments, such weakened portionscan comprise score marks, perforations, and/or thin cross-sections, forexample, which can facilitate a controlled collapse of the cartridgebody 1110. In at least one embodiment, the first layer 1111 can compriseone or more weakened portions which can facilitate the penetration ofthe staple legs 1121 through the first layer 1111. In variousembodiments, such weakened portions can comprise score marks,perforations, and/or thin cross-sections, for example, which can bealigned, or at least substantially aligned, with the staple legs 1121.

When the anvil 1140 is in a partially closed, unfired position,referring again to FIG. 7A, the anvil 1140 can be positioned a distance1101 a away from the cartridge support surface 1131 such that a gap isdefined therebetween. This gap can be filled by the staple cartridge1100, having a staple cartridge height 1102 a, and the tissue T. As theanvil 1140 is moved downwardly to compress the staple cartridge 1100,referring again to FIG. 7B, the distance between the tissue contactingsurface 1141 and the cartridge support surface 1131 can be defined by adistance 1101 b which is shorter than the distance 1101 a. In variouscircumstances, the gap between the tissue-contacting surface 1141 ofanvil 1140 and the cartridge support surface 1131, defined by distance1101 b, may be larger than the original, undeformed staple cartridgeheight 1102 a. As the anvil 1140 is moved closer to the cartridgesupport surface 1131, referring now to FIG. 7C, the second layer 1112can continue to collapse and the distance between the staple legs 1121and the forming pockets 1142 can decrease. Similarly, the distancebetween the tissue-contacting surface 1141 and the cartridge supportsurface 1131 can decrease to a distance 1101 c which, in variousembodiments, may be greater than, equal to, or less than the original,undeformed cartridge height 1102 a. Referring now to FIG. 7D, the anvil1140 can be moved into a final, fired position in which the staples 1120have been fully formed, or at least formed to a desired height. In sucha position, the tissue-contacting surface 1141 of anvil 1140 can be adistance 1101 d away from the cartridge support surface 1131, whereinthe distance 1101 d can be shorter than the original, undeformedcartridge height 1102 a. As also illustrated in FIG. 7D, the staplecavities 1115 may be fully, or at least substantially, collapsed and thestaples 1120 may be completely, or at least substantially, surrounded bythe collapsed second layer 1112. In various circumstances, the anvil1140 can be thereafter moved away from the staple cartridge 1100. Oncethe anvil 1140 has been disengaged from the staple cartridge 1100, thecartridge body 1110 can at least partially re-expand in variouslocations, i.e., locations intermediate adjacent staples 1120, forexample. In at least one embodiment, the crushed cartridge body 1110 maynot resiliently re-expand. In various embodiments, the formed staples1120 and, in addition, the cartridge body 1110 positioned intermediateadjacent staples 1120 may apply pressure, or compressive forces, to thetissue T which may provide various therapeutic benefits.

As discussed above, referring again to the embodiment illustrated inFIG. 7A, each staple 1120 can comprise staple legs 1121 extendingtherefrom. Although staples 1120 are depicted as comprising two staplelegs 1121, various staples can be utilized which can comprise one stapleleg or, alternatively, more than two staple legs, such as three staplelegs or four staple legs, for example. As illustrated in FIG. 7A, eachstaple leg 1121 can be embedded in the second layer 1112 of thecartridge body 1110 such that the staples 1120 are secured within thesecond layer 1112. In various embodiments, the staples 1120 can beinserted into the staple cavities 1115 in cartridge body 1110 such thatthe tips 1123 of the staple legs 1121 enter into the cavities 1115before the bases 1122. After the tips 1123 have been inserted into thecavities 1115, in various embodiments, the tips 1123 can be pressed intothe cover portions 1116 and incise the second layer 1112. In variousembodiments, the staples 1120 can be seated to a sufficient depth withinthe second layer 1112 such that the staples 1120 do not move, or atleast substantially move, relative to the second layer 1112. In certainembodiments, the staples 1120 can be seated to a sufficient depth withinthe second layer 1112 such that the bases 1122 are positioned orembedded within the staple cavities 1115. In various other embodiments,the bases 1122 may not be positioned or embedded within the second layer1112. In certain embodiments, referring again to FIG. 7A, the bases 1122may extend below the bottom surface 1118 of the cartridge body 1110. Incertain embodiments, the bases 1122 can rest on, or can be directlypositioned against, the cartridge support surface 1130. In variousembodiments, the cartridge support surface 1130 can comprise supportfeatures extending therefrom and/or defined therein wherein, in at leastone such embodiment, the bases 1122 of the staples 1120 may bepositioned within and supported by one or more support grooves, slots,or troughs, 1132, for example, in the staple cartridge support 1130, asdescribed in greater detail further below.

In various embodiments, referring now to FIGS. 8 and 9, a staplecartridge, such as staple cartridge 1200, for example, can comprise acompressible, implantable cartridge body 1210 comprising an outer layer1211 and an inner layer 1212. Similar to the above, the staple cartridge1200 can comprise a plurality of staples 1220 positioned within thecartridge body 1210. In various embodiments, each staple 1220 cancomprise a base 1222 and one or more staple legs 1221 extendingtherefrom. In at least one such embodiment, the staple legs 1221 can beinserted into the inner layer 1212 and seated to a depth in which thebases 1222 of the staples 1220 abut and/or are positioned adjacent tothe bottom surface 1218 of the inner layer 1212, for example. In theembodiment depicted in FIGS. 8 and 9, the inner layer 1212 does notcomprise staple cavities configured to receive a portion of the staples1220 while, in other embodiments, the inner layer 1212 can comprise suchstaple cavities. In various embodiments, further to the above, the innerlayer 1212 can be comprised of a compressible material, such asbioabsorbable foam and/or oxidized regenerated cellulose (ORC), forexample, which can be configured to allow the cartridge body 1210 tocollapse when a compressive load is applied thereto. In variousembodiments, the inner layer 1212 can be comprised of a lyophilized foamcomprising polylactic acid (PLA) and/or polyglycolic acid (PGA), forexample. The ORC may be commercially available under the trade nameSurgicel and can comprise a loose woven fabric (like a surgical sponge),loose fibers (like a cotton ball), and/or a foam. In at least oneembodiment, the inner layer 1212 can be comprised of a materialincluding medicaments, such as freeze-dried thrombin and/or fibrin, forexample, contained therein and/or coated thereon which can bewater-activated and/or activated by fluids within the patient's body,for example. In at least one such embodiment, the freeze-dried thrombinand/or fibrin can be held on a Vicryl (PGA) matrix, for example. Incertain circumstances, however, the activatable medicaments can beunintentionally activated when the staple cartridge 1200 is insertedinto a surgical site within the patient, for example. In variousembodiments, referring again to FIGS. 8 and 9, the outer layer 1211 canbe comprised of a water impermeable, or at least substantially waterimpermeable, material such that liquids do not come into contact with,or at least substantially contact, the inner layer 1212 until after thecartridge body 1210 has been compressed and the staple legs havepenetrated the outer layer 1211 and/or after the outer layer 1211 hasbeen incised in some fashion. In various embodiments, the outer layer1211 can be comprised of a buttress material and/or plastic material,such as polydioxanone (PDS) and/or polyglycolic acid (PGA), for example.In certain embodiments, the outer layer 1211 can comprise a wrap whichsurrounds the inner layer 1212 and the staples 1220. More particularly,in at least one embodiment, the staples 1220 can be inserted into theinner layer 1212 and the outer layer 1211 can be wrapped around thesub-assembly comprising the inner layer 1212 and the staples 1220 andthen sealed.

In various embodiments described herein, the staples of a staplecartridge can be fully formed by an anvil when the anvil is moved into aclosed position. In various other embodiments, referring now to FIGS.10-13, the staples of a staple cartridge, such as staple cartridge 4100,for example, can be deformed by an anvil when the anvil is moved into aclosed position and, in addition, by a staple driver system which movesthe staples toward the closed anvil. The staple cartridge 4100 cancomprise a compressible cartridge body 4110 which can be comprised of afoam material, for example, and a plurality of staples 4120 at leastpartially positioned within the compressible cartridge body 4110. Invarious embodiments, the staple driver system can comprise a driverholder 4160, a plurality of staple drivers 4162 positioned within thedriver holder 4160, and a staple cartridge pan 4180 which can beconfigured to retain the staple drivers 4162 in the driver holder 4160.In at least one such embodiment, the staple drivers 4162 can bepositioned within one or more slots 4163 in the driver holder 4160wherein the sidewalls of the slots 4163 can assist in guiding the stapledrivers 4162 upwardly toward the anvil. In various embodiments, thestaples 4120 can be supported within the slots 4163 by the stapledrivers 4162 wherein, in at least one embodiment, the staples 4120 canbe entirely positioned in the slots 4163 when the staples 4120 and thestaple drivers 4162 are in their unfired positions. In certain otherembodiments, at least a portion of the staples 4120 can extend upwardlythrough the open ends 4161 of slots 4163 when the staples 4120 andstaple drivers 4162 are in their unfired positions. In at least one suchembodiment, referring primarily now to FIG. 11, the bases of the staples4120 can be positioned within the driver holder 4160 and the tips of thestaples 4120 can be embedded within the compressible cartridge body4110. In certain embodiments, approximately one-third of the height ofthe staples 4120 can be positioned within the driver holder 4160 andapproximately two-thirds of the height of the staples 4120 can bepositioned within the cartridge body 4110. In at least one embodiment,referring to FIG. 10A, the staple cartridge 4100 can further comprise awater impermeable wrap or membrane 4111 surrounding the cartridge body4110 and the driver holder 4160, for example.

In use, the staple cartridge 4100 can be positioned within a staplecartridge channel, for example, and the anvil can be moved toward thestaple cartridge 4100 into a closed position. In various embodiments,the anvil can contact and compress the compressible cartridge body 4110when the anvil is moved into its closed position. In certainembodiments, the anvil may not contact the staples 4120 when the anvilis in its closed position. In certain other embodiments, the anvil maycontact the legs of the staples 4120 and at least partially deform thestaples 4120 when the anvil is moved into its closed position. In eitherevent, the staple cartridge 4100 can further comprise one or more sleds4170 which can be advanced longitudinally within the staple cartridge4100 such that the sleds 4170 can sequentially engage the staple drivers4162 and move the staple drivers 4162 and the staples 4120 toward theanvil. In various embodiments, the sleds 4170 can slide between thestaple cartridge pan 4180 and the staple drivers 4162. In embodimentswhere the closure of the anvil has started the forming process of thestaples 4120, the upward movement of the staples 4120 toward the anvilcan complete the forming process and deform the staples 4120 to theirfully formed, or at least desired, height. In embodiments where theclosure of the anvil has not deformed the staples 4120, the upwardmovement of the staples 4120 toward the anvil can initiate and completethe forming process and deform the staples 4120 to their fully formed,or at least desired, height. In various embodiments, the sleds 4170 canbe advanced from a proximal end of the staple cartridge 4100 to a distalend of the staple cartridge 4100 such that the staples 4120 positionedin the proximal end of the staple cartridge 4100 are fully formed beforethe staples 4120 positioned in the distal end of the staple cartridge4100 are fully formed. In at least one embodiment, referring to FIG. 12,the sleds 4170 can each comprise at least one angled or inclined surface4711 which can be configured to slide underneath the staple drivers 4162and lift the staple drivers 4162 as illustrated in FIG. 13.

In various embodiments, further to the above, the staples 4120 can beformed in order to capture at least a portion of the tissue T and atleast a portion of the compressible cartridge body 4110 of the staplecartridge 4100 therein. After the staples 4120 have been formed, theanvil and the staple cartridge channel 4130 of the surgical stapler canbe moved away from the implanted staple cartridge 4100. In variouscircumstances, the cartridge pan 4180 can be fixedly engaged with thestaple cartridge channel 4130 wherein, as a result, the cartridge pan4180 can become detached from the compressible cartridge body 4110 asthe staple cartridge channel 4130 is pulled away from the implantedcartridge body 4110. In various embodiments, referring again to FIG. 10,the cartridge pan 4180 can comprise opposing side walls 4181 betweenwhich the cartridge body 4110 can be removably positioned. In at leastone such embodiment, the compressible cartridge body 4110 can becompressed between the side walls 4181 such that the cartridge body 4110can be removably retained therebetween during use and releasablydisengaged from the cartridge pan 4180 as the cartridge pan 4180 ispulled away. In at least one such embodiment, the driver holder 4160 canbe connected to the cartridge pan 4180 such that the driver holder 4160,the drivers 4162, and/or the sleds 4170 can remain in the cartridge pan4180 when the cartridge pan 4180 is removed from the surgical site. Incertain other embodiments, the drivers 4162 can be ejected from thedriver holder 4160 and left within the surgical site. In at least onesuch embodiment, the drivers 4162 can be comprised of a bioabsorbablematerial, such as polyglycolic acid (PGA) which is marketed under thetrade name Vicryl, polylactic acid (PLA or PLLA), polydioxanone (PDS),polyhydroxyalkanoate (PHA), poliglecaprone 25 (PGCL) which is marketedunder the trade name Monocryl, polycaprolactone (PCL), and/or acomposite of PGA, PLA, PDS, PHA, PGCL and/or PCL, for example. Invarious embodiments, the drivers 4162 can be attached to the staples4120 such that the drivers 4162 are deployed with the staples 4120. Inat least one such embodiment, each driver 4162 can comprise a troughconfigured to receive the bases of the staples 4120, for example,wherein, in at least one embodiment, the troughs can be configured toreceive the staple bases in a press-fit and/or snap-fit manner.

In certain embodiments, further to the above, the driver holder 4160and/or the sleds 4170 can be ejected from the cartridge pan 4180. In atleast one such embodiment, the sleds 4170 can slide between thecartridge pan 4180 and the driver holder 4160 such that, as the sleds4170 are advanced in order to drive the staple drivers 4162 and staples4120 upwardly, the sleds 4170 can move the driver holder 4160 upwardlyout of the cartridge pan 4180 as well. In at least one such embodiment,the driver holder 4160 and/or the sleds 4170 can be comprised of abioabsorbable material, such as polyglycolic acid (PGA) which ismarketed under the trade name Vicryl, polylactic acid (PLA or PLLA),polydioxanone (PDS), polyhydroxyalkanoate (PHA), poliglecaprone 25(PGCL) which is marketed under the trade name Monocryl, polycaprolactone(PCL), and/or a composite of PGA, PLA, PDS, PHA, PGCL and/or PCL, forexample. In various embodiments, the sleds 4170 can be integrally formedand/or attached to a drive bar, or cutting member, which pushes thesleds 4170 through the staple cartridge 4100. In such embodiments, thesleds 4170 may not be ejected from the cartridge pan 4180 and may remainwith the surgical stapler while, in other embodiments in which the sleds4170 are not attached to the drive bar, the sleds 4170 may be left inthe surgical site. In any event, further to the above, thecompressibility of the cartridge body 4110 can allow thicker staplecartridges to be used within an end effector of a surgical stapler asthe cartridge body 4110 can compress, or shrink, when the anvil of thestapler is closed. In certain embodiments, as a result of the staplesbeing at least partially deformed upon the closure of the anvil, tallerstaples, such as staples having an approximately 0.18″ staple height,for example, could be used, wherein approximately 0.12″ of the stapleheight can be positioned within the compressible layer 4110 and whereinthe compressible layer 4110 can have an uncompressed height ofapproximately 0.14″, for example.

In many embodiments described herein, a staple cartridge can comprise aplurality of staples therein. In various embodiments, such staples canbe comprised of a metal wire deformed into a substantially U-shapedconfiguration having two staple legs. Other embodiments are envisionedin which staples can comprise different configurations such as two ormore wires that have been joined together having three or more staplelegs. In various embodiments, the wire, or wires, used to form thestaples can comprise a round, or at least substantially round,cross-section. In at least one embodiment, the staple wires can compriseany other suitable cross-section, such as square and/or rectangularcross-sections, for example. In certain embodiments, the staples can becomprised of plastic wires. In at least one embodiment, the staples canbe comprised of plastic-coated metal wires. In various embodiments, acartridge can comprise any suitable type of fastener in addition to orin lieu of staples. In at least one such embodiment, such a fastener cancomprise pivotable arms which are folded when engaged by an anvil. Incertain embodiments, two-part fasteners could be utilized. In at leastone such embodiment, a staple cartridge can comprise a plurality offirst fastener portions and an anvil can comprise a plurality of secondfastener portions which are connected to the first fastener portionswhen the anvil is compressed against the staple cartridge. In certainembodiments, as described above, a sled or driver can be advanced withina staple cartridge in order to complete the forming process of thestaples. In certain embodiments, a sled or driver can be advanced withinan anvil in order to move one or more forming members downwardly intoengagement with the opposing staple cartridge and the staples, orfasteners, positioned therein.

In various embodiments described herein, a staple cartridge can comprisefour rows of staples stored therein. In at least one embodiment, thefour staple rows can be arranged in two inner staple rows and two outerstaple rows. In at least one such embodiment, an inner staple row and anouter staple row can be positioned on a first side of a cutting member,or knife, slot within the staple cartridge and, similarly, an innerstaple row and an outer staple row can be positioned on a second side ofthe cutting member, or knife, slot. In certain embodiments, a staplecartridge may not comprise a cutting member slot; however, such a staplecartridge may comprise a designated portion configured to be incised bya cutting member in lieu of a staple cartridge slot. In variousembodiments, the inner staple rows can be arranged within the staplecartridge such that they are equally, or at least substantially equally,spaced from the cutting member slot. Similarly, the outer staple rowscan be arranged within the staple cartridge such that they are equally,or at least substantially equally, spaced from the cutting member slot.In various embodiments, a staple cartridge can comprise more than orless than four rows of staples stored within a staple cartridge. In atleast one embodiment, a staple cartridge can comprise six rows ofstaples. In at least one such embodiment, the staple cartridge cancomprise three rows of staples on a first side of a cutting member slotand three rows of staples on a second side of the cutting member slot.In certain embodiments, a staple cartridge may comprise an odd number ofstaple rows. For example, a staple cartridge may comprise two rows ofstaples on a first side of a cutting member slot and three rows ofstaples on a second side of the cutting member slot. In variousembodiments, the staple rows can comprise staples having the same, or atleast substantially the same, unformed staple height. In certain otherembodiments, one or more of the staple rows can comprise staples havinga different unformed staple height than the other staples. In at leastone such embodiment, the staples on a first side of a cutting memberslot may have a first unformed height and the staples on a second sideof a cutting member slot may have a second unformed height which isdifferent than the first height, for example.

In various embodiments, as described above, a staple cartridge cancomprise a cartridge body including a plurality of staple cavitiesdefined therein. The cartridge body can comprise a deck and a top decksurface wherein each staple cavity can define an opening in the decksurface. As also described above, a staple can be positioned within eachstaple cavity such that the staples are stored within the cartridge bodyuntil they are ejected therefrom. Prior to being ejected from thecartridge body, in various embodiments, the staples can be containedwiththe cartridge body such that the staples do not protrude above the decksurface. As the staples are positioned below the deck surface, in suchembodiments, the possibility of the staples becoming damaged and/orprematurely contacting the targeted tissue can be reduced. In variouscircumstances, the staples can be moved between an unfired position inwhich they do not protrude from the cartridge body and a fired positionin which they have emerged from the cartridge body and can contact ananvil positioned opposite the staple cartridge. In various embodiments,the anvil, and/or the forming pockets defined within the anvil, can bepositioned a predetermined distance above the deck surface such that, asthe staples are being deployed from the cartridge body, the staples aredeformed to a predetermined formed height. In some circumstances, thethickness of the tissue captured between the anvil and the staplecartridge may vary and, as a result, thicker tissue may be capturedwithin certain staples while thinner tissue may be captured withincertain other staples. In either event, the clamping pressure, or force,applied to the tissue by the staples may vary from staple to staple orvary between a staple on one end of a staple row and a staple on theother end of the staple row, for example. In certain circumstances, thegap between the anvil and the staple cartridge deck can be controlledsuch that the staples apply a certain minimum clamping pressure withineach staple. In some such circumstances, however, significant variationof the clamping pressure within different staples may still exist.Surgical stapling instruments are disclosed in U.S. Pat. No. 7,380,696,which issued on Jun. 3, 2008, the entire disclosure of which isincorporated by reference herein. An illustrative multi-stroke handlefor the surgical stapling and severing instrument is described ingreater detail in the co-owned U.S. patent application entitled SURGICALSTAPLING INSTRUMENT INCORPORATING A MULTISTROKE FIRING POSITIONINDICATOR AND RETRACTION MECHANISM, Ser. No. 10/674,026, now U.S. Pat.No. 7,364,061, the disclosure of which is hereby incorporated byreference in its entirety. Other applications consistent with thepresent invention may incorporate a single firing stroke, such asdescribed in commonly owned U.S. patent application SURGICAL STAPLINGINSTRUMENT HAVING SEPARATE DISTINCT CLOSING AND FIRING SYSTEMS, Ser. No.10/441,632, now U.S. Pat. No. 7,000,818, the disclosure of which ishereby incorporated by reference in its entirety.

In various embodiments described herein, a staple cartridge can comprisemeans for compensating for the thickness of the tissue captured withinthe staples deployed from the staple cartridge. In various embodiments,referring to FIG. 14, a staple cartridge, such as staple cartridge10000, for example, can include a rigid first portion, such as supportportion 10010, for example, and a compressible second portion, such astissue thickness compensator 10020, for example. In at least oneembodiment, referring primarily to FIG. 16, the support portion 10010can comprise a cartridge body, a top deck surface 10011, and a pluralityof staple cavities 10012 wherein, similar to the above, each staplecavity 10012 can define an opening in the deck surface 10011. A staple10030, for example, can be removably positioned in each staple cavity10012. In at least one such embodiment, each staple 10030 can comprise abase 10031 and one or more legs 10032 extending from the base 10031.Prior to the staples 10030 being deployed, as also described in greaterdetail below, the bases 10031 of the staples 10030 can be supported bystaple drivers positioned within the support portion 10010 and,concurrently, the legs 10032 of the staples 10030 can be at leastpartially contained within the staple cavities 10012. In variousembodiments, the staples 10030 can be deployed between an unfiredposition and a fired position such that the legs 10032 move through thetissue thickness compensator 10020, penetrate through a top surface ofthe tissue thickness compensator 10020, penetrate the tissue T, andcontact an anvil positioned opposite the staple cartridge 10000. As thelegs 10032 are deformed against the anvil, the legs 10032 of each staple10030 can capture a portion of the tissue thickness compensator 10020and a portion of the tissue T within each staple 10030 and apply acompressive force to the tissue. Further to the above, the legs 10032 ofeach staple 10030 can be deformed downwardly toward the base 10031 ofthe staple to form a staple entrapment area 10039 in which the tissue Tand the tissue thickness compensator 10020 can be captured. In variouscircumstances, the staple entrapment area 10039 can be defined betweenthe inner surfaces of the deformed legs 10032 and the inner surface ofthe base 10031. The size of the entrapment area for a staple can dependon several factors such as the length of the legs, the diameter of thelegs, the width of the base, and/or the extent in which the legs aredeformed, for example.

In previous embodiments, a surgeon was often required to select theappropriate staples having the appropriate staple height for the tissuebeing stapled. For example, a surgeon could select tall staples for usewith thick tissue and short staples for use with thin tissue. In somecircumstances, however, the tissue being stapled did not have aconsistent thickness and, thus, some staples were unable to achieve thedesired fired configuration. For example, FIG. 48 illustrates a tallstaple used in thin tissue. Referring now to FIG. 49, when a tissuethickness compensator, such as tissue thickness compensator 10020, forexample, is used with thin tissue, for example, the larger staple may beformed to a desired fired configuration.

Owing to the compressibility of the tissue thickness compensator, thetissue thickness compensator can compensate for the thickness of thetissue captured within each staple. More particularly, referring now toFIGS. 43 and 44, a tissue thickness compensator, such as tissuethickness compensator 10020, for example, can consume larger and/orsmaller portions of the staple entrapment area 10039 of each staple10030 depending on the thickness and/or type of tissue contained withinthe staple entrapment area 10039. For example, if thinner tissue T iscaptured within a staple 10030, the tissue thickness compensator 10020can consume a larger portion of the staple entrapment area 10039 ascompared to circumstances where thicker tissue T is captured within thestaple 10030. Correspondingly, if thicker tissue T is captured within astaple 10030, the tissue thickness compensator 10020 can consume asmaller portion of the staple entrapment area 10039 as compared to thecircumstances where thinner tissue T is captured within the staple10030. In this way, the tissue thickness compensator can compensate forthinner tissue and/or thicker tissue and assure that a compressivepressure is applied to the tissue irrespective, or at leastsubstantially irrespective, of the tissue thickness captured within thestaples. In addition to the above, the tissue thickness compensator10020 can compensate for different types, or compressibilities, oftissues captured within different staples 10030. Referring now to FIG.44, the tissue thickness compensator 10020 can apply a compressive forceto vascular tissue T which can include vessels V and, as a result,restrict the flow of blood through the less compressible vessels V whilestill applying a desired compressive pressure to the surrounding tissueT. In various circumstances, further to the above, the tissue thicknesscompensator 10020 can also compensate for malformed staples. Referringto FIG. 45, the malformation of various staples 10030 can result inlarger staple entrapment areas 10039 being defined within such staples.Owing to the resiliency of the tissue thickness compensator 10020,referring now to FIG. 46, the tissue thickness compensator 10020positioned within malformed staples 10030 may still apply a sufficientcompressive pressure to the tissue T even though the staple entrapmentareas 10039 defined within such malformed staples 10030 may be enlarged.In various circumstances, the tissue thickness compensator 10020 locatedintermediate adjacent staples 10030 can be biased against the tissue Tby properly-formed staples 10030 surrounding a malformed staple 10030and, as a result, apply a compressive pressure to the tissue surroundingand/or captured within the malformed staple 10030, for example. Invarious circumstances, a tissue thickness compensator can compensate fordifferent tissue densities which can arise due to calcifications,fibrous areas, and/or tissue that has been previously stapled ortreated, for example.

In various embodiments, a fixed, or unchangeable, tissue gap can bedefined between the support portion and the anvil and, as a result, thestaples may be deformed to a predetermined height regardless of thethickness of the tissue captured within the staples. When a tissuethickness compensator is used with these embodiments, the tissuethickness compensator can adapt to the tissue captured between the anviland the support portion staple cartridge and, owing to the resiliency ofthe tissue thickness compensator, the tissue thickness compensator canapply an additional compressive pressure to the tissue. Referring now toFIGS. 50-55, a staple 10030 has been formed to a predefined height H.With regard to FIG. 50, a tissue thickness compensator has not beenutilized and the tissue T consumes the entirety of the staple entrapmentarea 10039. With regard to FIG. 57, a portion of a tissue thicknesscompensator 10020 has been captured within the staple 10030, compressedthe tissue T, and consumed at least a portion of the staple entrapmentarea 10039. Referring now to FIG. 52, thin tissue T has been capturedwithin the staple 10030. In this embodiment, the compressed tissue T hasa height of approximately 2/9H and the compressed tissue thicknesscompensator 10020 has a height of approximately 7/9H, for example.Referring now to FIG. 53, tissue T having an intermediate thickness hasbeen captured within the staple 10030. In this embodiment, thecompressed tissue T has a height of approximately 4/9H and thecompressed tissue thickness compensator 10020 has a height ofapproximately 5/9H, for example. Referring now to FIG. 54, tissue Thaving an intermediate thickness has been captured within the staple10030. In this embodiment, the compressed tissue T has a height ofapproximately 2/3H and the compressed tissue thickness compensator 10020has a height of approximately 1/3H, for example. Referring now to FIG.53, thick tissue T has been captured within the staple 10030. In thisembodiment, the compressed tissue T has a height of approximately 8/9Hand the compressed tissue thickness compensator 10020 has a height ofapproximately 1/9H, for example. In various circumstances, the tissuethickness compensator can comprise a compressed height which comprisesapproximately 10% of the staple entrapment height, approximately 20% ofthe staple entrapment height, approximately 30% of the staple entrapmentheight, approximately 40% of the staple entrapment height, approximately50% of the staple entrapment height, approximately 60% of the stapleentrapment height, approximately 70% of the staple entrapment height,approximately 80% of the staple entrapment height, and/or approximately90% of the staple entrapment height, for example.

In various embodiments, the staples 10030 can comprise any suitableunformed height. In certain embodiments, the staples 10030 can comprisean unformed height between approximately 2 mm and approximately 4.8 mm,for example. The staples 10030 can comprise an unformed height ofapproximately 2.0 mm, approximately 2.5 mm, approximately 3.0 mm,approximately 3.4 mm, approximately 3.5 mm, approximately 3.8 mm,approximately 4.0 mm, approximately 4.1 mm, and/or approximately 4.8 mm,for example. In various embodiments, the height H to which the staplescan be deformed can be dictated by the distance between the deck surface10011 of the support portion 10010 and the opposing anvil. In at leastone embodiment, the distance between the deck surface 10011 and thetissue-contacting surface of the anvil can be approximately 0.097″, forexample. The height H can also be dictated by the depth of the formingpockets defined within the anvil. In at least one embodiment, theforming pockets can have a depth measured from the tissue-contactingsurface, for example. In various embodiments, as described in greaterdetail below, the staple cartridge 10000 can further comprise stapledrivers which can lift the staples 10030 toward the anvil and, in atleast one embodiment, lift, or “overdrive”, the staples above the decksurface 10011. In such embodiments, the height H to which the staples10030 are formed can also be dictated by the distance in which thestaples 10030 are overdriven. In at least one such embodiment, thestaples 10030 can be overdriven by approximately 0.028″, for example,and can result in the staples 10030 being formed to a height ofapproximately 0.189″, for example. In various embodiments, the staples10030 can be formed to a height of approximately 0.8 mm, approximately1.0 mm, approximately 1.5 mm, approximately 1.8 mm, approximately 2.0mm, and/or approximately 2.25 mm, for example. In certain embodiments,the staples can be formed to a height between approximately 2.25 mm andapproximately 3.0 mm, for example. Further to the above, the height ofthe staple entrapment area of a staple can be determined by the formedheight of the staple and the width, or diameter, of the wire comprisingthe staple. In various embodiments, the height of the staple entrapmentarea 10039 of a staple 10030 can comprise the formed height H of thestaple less two diameter widths of the wire. In certain embodiments, thestaple wire can comprise a diameter of approximately 0.0089″, forexample. In various embodiments, the staple wire can comprise a diameterbetween approximately 0.0069″ and approximately 0.0119″, for example. Inat least one exemplary embodiment, the formed height H of a staple 10030can be approximately 0.189″ and the staple wire diameter can beapproximately 0.0089″ resulting in a staple entrapment height ofapproximately 0.171″, for example.

In various embodiments, further to the above, the tissue thicknesscompensator can comprise an uncompressed, or pre-deployed, height andcan be configured to deform to one of a plurality of compressed heights.In certain embodiments, the tissue thickness compensator can comprise anuncompressed height of approximately 0.125″, for example. In variousembodiments, the tissue thickness compensator can comprise anuncompressed height of greater than or equal to approximately 0.080″,for example. In at least one embodiment, the tissue thicknesscompensator can comprise an uncompressed, or pre-deployed, height whichis greater than the unfired height of the staples. In at least oneembodiment, the uncompressed, or pre-deployed, height of the tissuethickness compensator can be approximately 10% taller, approximately 20%taller, approximately 30% taller, approximately 40% taller,approximately 50% taller, approximately 60% taller, approximately 70%taller, approximately 80% taller, approximately 90% taller, and/orapproximately 100% taller than the unfired height of the staples, forexample. In at least one embodiment, the uncompressed, or pre-deployed,height of the tissue thickness compensator can be up to approximately100% taller than the unfired height of the staples, for example. Incertain embodiments, the uncompressed, or pre-deployed, height of thetissue thickness compensator can be over 100% taller than the unfiredheight of the staples, for example. In at least one embodiment, thetissue thickness compensator can comprise an uncompressed height whichis equal to the unfired height of the staples. In at least oneembodiment, the tissue thickness compensator can comprise anuncompressed height which is less than the unfired height of thestaples. In at least one embodiment, the uncompressed, or pre-deployedheight of the thickness compensator can be approximately 10% shorter,approximately 20% shorter, approximately 30% shorter, approximately 40%shorter, approximately 50% shorter, approximately 60% shorter,approximately 70% shorter, approximately 80% shorter, and/orapproximately 90% shorter than the unfired height of the staples, forexample. In various embodiments, the compressible second portion cancomprise an uncompressed height which is taller than an uncompressedheight of the tissue T being stapled. In certain embodiments, the tissuethickness compensator can comprise an uncompressed height which is equalto an uncompressed height of the tissue T being stapled. In variousembodiments, the tissue thickness compensator can comprise anuncompressed height which is shorter than an uncompressed height of thetissue T being stapled.

As described above, a tissue thickness compensator can be compressedwithin a plurality of formed staples regardless of whether thick tissueor thin tissue is captured within the staples. In at least one exemplaryembodiment, the staples within a staple line, or row, can be deformedsuch that the staple entrapment area of each staple comprises a heightof approximately 2.0 mm, for example, wherein the tissue T and thetissue thickness compensator can be compressed within this height. Incertain circumstances, the tissue T can comprise a compressed height ofapproximately 1.75 mm within the staple entrapment area while the tissuethickness compensator can comprise a compressed height of approximately0.25 mm within the staple entrapment area, thereby totaling theapproximately 2.0 mm staple entrapment area height, for example. Incertain circumstances, the tissue T can comprise a compressed height ofapproximately 1.50 mm within the staple entrapment area while the tissuethickness compensator can comprise a compressed height of approximately0.50 mm within the staple entrapment area, thereby totaling theapproximately 2.0 mm staple entrapment area height, for example. Incertain circumstances, the tissue T can comprise a compressed height ofapproximately 1.25 mm within the staple entrapment area while the tissuethickness compensator can comprise a compressed height of approximately0.75 mm within the staple entrapment area, thereby totaling theapproximately 2.0 mm staple entrapment area height, for example. Incertain circumstances, the tissue T can comprise a compressed height ofapproximately 1.0 mm within the staple entrapment area while the tissuethickness compensator can comprise a compressed height of approximately1.0 mm within the staple entrapment area, thereby totaling theapproximately 2.0 mm staple entrapment area height, for example. Incertain circumstances, the tissue T can comprise a compressed height ofapproximately 0.75 mm within the staple entrapment area while the tissuethickness compensator can comprise a compressed height of approximately1.25 mm within the staple entrapment area, thereby totaling theapproximately 2.0 mm staple entrapment area height, for example. Incertain circumstances, the tissue T can comprise a compressed height ofapproximately 1.50 mm within the staple entrapment area while the tissuethickness compensator can comprise a compressed height of approximately0.50 mm within the staple entrapment area, thereby totaling theapproximately 2.0 mm staple entrapment area height, for example. Incertain circumstances, the tissue T can comprise a compressed height ofapproximately 0.25 mm within the staple entrapment area while the tissuethickness compensator can comprise a compressed height of approximately1.75 mm within the staple entrapment area, thereby totaling theapproximately 2.0 mm staple entrapment area height, for example.

In various embodiments, further to the above, the tissue thicknesscompensator can comprise an uncompressed height which is less than thefired height of the staples. In certain embodiments, the tissuethickness compensator can comprise an uncompressed height which is equalto the fired height of the staples. In certain other embodiments, thetissue thickness compensator can comprise an uncompressed height whichis taller than the fired height of the staples. In at least one suchembodiment, the uncompressed height of a tissue thickness compensatorcan comprise a thickness which is approximately 110% of the formedstaple height, approximately 120% of the formed staple height,approximately 130% of the formed staple height, approximately 140% ofthe formed staple height, approximately 150% of the formed stapleheight, approximately 160% of the formed staple height, approximately170% of the formed staple height, approximately 180% of the formedstaple height, approximately 190% of the formed staple height, and/orapproximately 200% of the formed staple height, for example. In certainembodiments, the tissue thickness compensator can comprise anuncompressed height which is more than twice the fired height of thestaples. In various embodiments, the tissue thickness compensator cancomprise a compressed height which is from approximately 85% toapproximately 150% of the formed staple height, for example. In variousembodiments, as described above, the tissue thickness compensator can becompressed between an uncompressed thickness and a compressed thickness.In certain embodiments, the compressed thickness of a tissue thicknesscompensator can be approximately 10% of its uncompressed thickness,approximately 20% of its uncompressed thickness, approximately 30% ofits uncompressed thickness, approximately 40% of its uncompressedthickness, approximately 50% of its uncompressed thickness,approximately 60% of its uncompressed thickness, approximately 70% ofits uncompressed thickness, approximately 80% of its uncompressedthickness, and/or approximately 90% of its uncompressed thickness, forexample. In various embodiments, the uncompressed thickness of thetissue thickness compensator can be approximately two times,approximately ten times, approximately fifty times, and/or approximatelyone hundred times thicker than its compressed thickness, for example. Inat least one embodiment, the compressed thickness of the tissuethickness compensator can be between approximately 60% and approximately99% of its uncompressed thickness. In at least one embodiment, theuncompressed thickness of the tissue thickness compensator can be atleast 50% thicker than its compressed thickness. In at least oneembodiment, the uncompressed thickness of the tissue thicknesscompensator can be up to one hundred times thicker than its compressedthickness. In various embodiments, the compressible second portion canbe elastic, or at least partially elastic, and can bias the tissue Tagainst the deformed legs of the staples. In at least one suchembodiment, the compressible second portion can resiliently expandbetween the tissue T and the base of the staple in order to push thetissue T against the legs of the staple. In certain embodiments,discussed in further detail below, the tissue thickness compensator canbe positioned intermediate the tissue T and the deformed staple legs. Invarious circumstances, as a result of the above, the tissue thicknesscompensator can be configured to consume any gaps within the stapleentrapment area.

In various embodiments, the tissue thickness compensator may comprisematerials characterized by one or more of the following properties:biocompatible, bioabsorable, bioresorbable, biodurable, biodegradable,compressible, fluid absorbable, swellable, self-expandable, bioactive,medicament, pharmaceutically active, anti-adhesion, haemostatic,antibiotic, anti-microbial, anti-viral, nutritional, adhesive,permeable, hydrophilic and/or hydrophobic, for example. In variousembodiments, a surgical instrument comprising an anvil and a staplecartridge may comprise a tissue thickness compensator associated withthe anvil and/or staple cartridge comprising at least one of ahaemostatic agent, such as fibrin and thrombin, an antibiotic, such asdoxycpl, and medicament, such as matrix metalloproteinases (MMPs).

In various embodiments, the tissue thickness compensator may comprisesynthetic and/or non-synthetic materials. The tissue thicknesscompensator may comprise a polymeric composition comprising one or moresynthetic polymers and/or one or more non-synthetic polymers. Thesynthetic polymer may comprise a synthetic absorbable polymer and/or asynthetic non-absorbable polymer. In various embodiments, the polymericcomposition may comprise a biocompatible foam, for example. Thebiocompatible foam may comprise a porous, open cell foam and/or aporous, closed cell foam, for example. The biocompatible foam may have auniform pore morphology or may have a gradient pore morphology (i.e.small pores gradually increasing in size to large pores across thethickness of the foam in one direction). In various embodiments, thepolymeric composition may comprise one or more of a porous scaffold, aporous matrix, a gel matrix, a hydrogel matrix, a solution matrix, afilamentous matrix, a tubular matrix, a composite matrix, a membranousmatrix, a biostable polymer, and a biodegradable polymer, andcombinations thereof. For example, the tissue thickness compensator maycomprise a foam reinforced by a filamentous matrix or may comprise afoam having an additional hydrogel layer that expands in the presence ofbodily fluids to further provide the compression on the tissue. Invarious embodiments, a tissue thickness compensator could also becomprised of a coating on a material and/or a second or third layer thatexpands in the presence of bodily fluids to further provide thecompression on the tissue. Such a layer could be a hydrogel that couldbe a synthetic and/or naturally derived material and could be eitherbiodurable and/or biodegradable, for example. In various embodiments,the tissue thickness compensator may comprise a microgel or a nanogel.The hydrogel may comprise carbohydrate-derived microgels and/ornanogels. In certain embodiments, a tissue thickness compensator may bereinforced with fibrous non-woven materials or fibrous mesh typeelements, for example, that can provide additional flexibility,stiffness, and/or strength. In various embodiments, a tissue thicknesscompensator that has a porous morphology which exhibits a gradientstructure such as, for example, small pores on one surface and largerpores on the other surface. Such morphology could be more optimal fortissue in-growth or haemostatic behavior. Further, the gradient could bealso compositional with a varying bio-absorption profile. A short termabsorption profile may be preferred to address hemostasis while a longterm absorption profile may address better tissue healing withoutleakages.

Examples of non-synthetic materials include, but are not limited to,lyophilized polysaccharide, glycoprotein, bovine pericardium, collagen,gelatin, fibrin, fibrinogen, elastin, proteoglycan, keratin, albumin,hydroxyethyl cellulose, cellulose, oxidized cellulose, oxidizedregenerated cellulose (ORC), hydroxypropyl cellulose, carboxyethylcellulose, carboxymethylcellulose, chitan, chitosan, casein, alginate,and combinations thereof.

Examples of synthetic absorbable materials include, but are not limitedto, poly(lactic acid) (PLA), poly(L-lactic acid) (PLLA),polycaprolactone (PCL), polyglycolic acid (PGA), poly(trimethylenecarbonate) (TMC), polyethylene terephthalate (PET), polyhydroxyalkanoate(PHA), a copolymer of glycolide and ε-caprolactone (PGCL), a copolymerof glycolide and-trimethylene carbonate, poly(glycerol sebacate) (PGS),poly(dioxanone) (PDS), polyesters, poly(orthoesters), polyoxaesters,polyetheresters, polycarbonates, polyamide esters, polyanhydrides,polysaccharides, poly(ester-amides), tyrosine-based polyarylates,polyamines, tyrosine-based polyiminocarbonates, tyrosine-basedpolycarbonates, poly(D,L-lactide-urethane), poly(hydroxybutyrate),poly(B-hydroxybutyrate), poly(E-caprolactone), polyethyleneglycol (PEG),poly[bis(carboxylatophenoxy)phosphazene]poly(amino acids),pseudo-poly(amino acids), absorbable polyurethanes, poly(phosphazine),polyphosphazenes, polyalkyleneoxides, polyacrylamides,polyhydroxyethylmethylacrylate, polyvinylpyrrolidone, polyvinylalcohols, poly(caprolactone), polyacrylic acid, polyacetate,polypropylene, aliphatic polyesters, glycerols, copoly(ether-esters),polyalkylene oxalates, polyamides, poly(iminocarbonates), polyalkyleneoxalates, and combinations thereof. In various embodiments, thepolyester is may be selected from the group consisting of polylactides,polyglycolides, trimethylene carbonates, polydioxanones,polycaprolactones, polybutesters, and combinations thereof.

In various embodiments, the synthetic absorbable polymer may compriseone or more of 90/10 poly(glycolide-L-lactide) copolymer, commerciallyavailable from Ethicon, Inc. under the trade designation VICRYL(polyglactic 910), polyglycolide, commercially available from AmericanCyanamid Co. under the trade designation DEXON, polydioxanone,commercially available from Ethicon, Inc. under the trade designationPDS, poly(glycolide-trimethylene carbonate) random block copolymer,commercially available from American Cyanamid Co. under the tradedesignation MAXON, 75/25poly(glycolide-ε-caprolactone-poliglecaprolactone 25) copolymer,commercially available from Ethicon under the trade designationMONOCRYL, for example.

Examples of synthetic non-absorbable materials include, but are notlimited to, polyurethane, polypropylene (PP), polyethylene (PE),polycarbonate, polyamides, such as nylon, polyvinylchloride (PVC),polymethylmetacrylate (PMMA), polystyrene (PS), polyester,polyetheretherketone (PEEK), polytetrafluoroethylene (PTFE),polytrifluorochloroethylene (PTFCE), polyvinylfluoride (PVF),fluorinated ethylene propylene (FEP), polyacetal, polysulfone, silicons,and combinations thereof. The synthetic non-absorbable polymers mayinclude, but are not limited to, foamed elastomers and porouselastomers, such as, for example, silicone, polyisoprene, and rubber. Invarious embodiments, the synthetic polymers may comprise expandedpolytetrafluoroethylene (ePTFE), commercially available from W. L. Gore& Associates, Inc. under the trade designation GORE-TEX Soft TissuePatch and co-polyetherester urethane foam commercially available fromPolyganics under the trade designation NASOPORE.

In various embodiments, the polymeric composition may comprise fromapproximately 50% to approximately 90% by weight of the polymericcomposition of PLLA and approximately 50% to approximately 10% by weightof the polymeric composition of PCL, for example. In at least oneembodiment, the polymeric composition may comprise approximately 70% byweight of PLLA and approximately 30% by weight of PCL, for example. Invarious embodiments, the polymeric composition may comprise fromapproximately 55% to approximately 85% by weight of the polymericcomposition of PGA and 15% to 45% by weight of the polymeric compositionof PCL, for example. In at least one embodiment, the polymericcomposition may comprise approximately 65% by weight of PGA andapproximately 35% by weight of PCL, for example. In various embodiments,the polymeric composition may comprise from approximately 90% toapproximately 95% by weight of the polymeric composition of PGA andapproximately 5% to approximately 10% by weight of the polymericcomposition of PLA, for example.

In various embodiments, the synthetic absorbable polymer may comprise abioabsorbable, biocompatible elastomeric copolymer. Suitablebioabsorbable, biocompatible elastomeric copolymers include but are notlimited to copolymers of ε-caprolactone and glycolide (preferably havinga mole ratio of ε-caprolactone to glycolide of from about 30:70 to about70:30, preferably 35:65 to about 65:35, and more preferably 45:55 to35:65); elastomeric copolymers of ε-caprolactone and lactide, includingL-lactide, D-lactide blends thereof or lactic acid copolymers(preferably having a mole ratio of ε-caprolactone to lactide of fromabout 35:65 to about 65:35 and more preferably 45:55 to 30:70)elastomeric copolymers of p-dioxanone (1,4-dioxan-2-one) and lactideincluding L-lactide, D-lactide and lactic acid (preferably having a moleratio of p-dioxanone to lactide of from about 40:60 to about 60:40);elastomeric copolymers of ε-caprolactone and p-dioxanone (preferablyhaving a mole ratio of ε-caprolactone to p-dioxanone of from about 30:70to about 70:30); elastomeric copolymers of p-dioxanone and trimethylenecarbonate (preferably having a mole ratio of p-dioxanone to trimethylenecarbonate of from about 30:70 to about 70:30); elastomeric copolymers oftrimethylene carbonate and glycolide (preferably having a mole ratio oftrimethylene carbonate to glycolide of from about 30:70 to about 70:30);elastomeric copolymer of trimethylene carbonate and lactide includingL-lactide, D-lactide, blends thereof or lactic acid copolymers(preferably having a mole ratio of trimethylene carbonate to lactide offrom about 30:70 to about 70:30) and blends thereof. In one embodiment,the elastomeric copolymer is a copolymer of glycolide andε-caprolactone. In another embodiment, the elastomeric copolymer is acopolymer of lactide and ε-caprolactone.

The disclosures of U.S. Pat. No. 5,468,253, entitled ELASTOMERIC MEDICALDEVICE, which issued on Nov. 21, 1995, and U.S. Pat. No. 6,325,810,entitled FOAM BUTTRESS FOR STAPLING APPARATUS, which issued on Dec. 4,2001, are hereby incorporated by reference in their respectiveentireties.

In various embodiments, the tissue thickness compensator may comprise anemulsifier. Examples of emulsifiers may include, but are not limited to,water-soluble polymers, such as, polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), polypropylene glycol(PPG), PLURONICS, TWEENS, polysaccharides and combinations thereof.

In various embodiments, the tissue thickness compensator may comprise asurfactant. Examples of surfactants may include, but are not limited to,polyacrylic acid, methalose, methyl cellulose, ethyl cellulose, propylcellulose, hydroxy ethyl cellulose, carboxy methyl cellulose,polyoxyethylene cetyl ether, polyoxyethylene lauryl ether,polyoxyethylene octyl ether, polyoxyethylene octylphenyl ether,polyoxyethylene oleyl ether, polyoxyethylene sorbitan monolaurate,polyoxyethylene stearyl ether, polyoxyethylene nonylphenyl ether,dialkylphenoxy poly(ethyleneoxy)ethanol, and polyoxamers.

In various embodiments, the polymeric composition may comprise apharmaceutically active agent. The polymeric composition may release atherapeutically effective amount of the pharmaceutically active agent.In various embodiments, the pharmaceutically active agent may bereleased as the polymeric composition is desorbed/absorbed. In variousembodiments, the pharmaceutically active agent may be released intofluid, such as, for example, blood, passing over or through thepolymeric composition. Examples of pharmaceutically active agents mayinclude, but are not limited to, haemostatic agents and drugs, such as,for example, fibrin, thrombin, and oxidized regenerated cellulose (ORC);anti-inflammatory drugs, such as, for example, diclofenac, aspirin,naproxen, sulindac, and hydrocortisone; antibiotic and antimicrobialdrug or agents, such as, for example, triclosan, ionic silver,ampicillin, gentamicin, polymyxin B, chloramphenicol; and anticanceragents, such as, for example, cisplatin, mitomycin, adriamycin.

In various embodiments, the polymeric composition may comprise ahaemostatic material. The tissue thickness compensator may comprisehaemostatic materials comprising poly(lactic acid), poly(glycolic acid),poly(hydroxybutyrate), poly(caprolactone), poly(dioxanone),polyalkyleneoxides, copoly(ether-esters), collagen, gelatin, thrombin,fibrin, fibrinogen, fibronectin, elastin, albumin, hemoglobin,ovalbumin, polysaccharides, hyaluronic acid, chondroitin sulfate,hydroxyethyl starch, hydroxyethyl cellulose, cellulose, oxidizedcellulose, hydroxypropyl cellulose, carboxyethyl cellulose,carboxymethyl cellulose, chitan, chitosan, agarose, maltose,maltodextrin, alginate, clotting factors, methacrylate, polyurethanes,cyanoacrylates, platelet agonists, vasoconstrictors, alum, calcium, RGDpeptides, proteins, protamine sulfate, ε-amino caproic acid, ferricsulfate, ferric subsulfates, ferric chloride, zinc, zinc chloride,aluminum chloride, aluminum sulfates, aluminum acetates, permanganates,tannins, bone wax, polyethylene glycols, fucans and combinationsthereof. The tissue thickness compensator may be characterized byhaemostatic properties.

The polymeric composition of a tissue thickness compensator may becharacterized by percent porosity, pore size, and/or hardness, forexample. In various embodiments, the polymeric composition may have apercent porosity from approximately 30% by volume to approximately 99%by volume, for example. In certain embodiments, the polymericcomposition may have a percent porosity from approximately 60% by volumeto approximately 98% by volume, for example. In various embodiments, thepolymeric composition may have a percent porosity from approximately 85%by volume to approximately 97% by volume, for example. In at least oneembodiment, the polymeric composition may comprise approximately 70% byweight of PLLA and approximately 30% by weight of PCL, for example, andcan comprise approximately 90% porosity by volume, for example. In atleast one such embodiment, as a result, the polymeric composition wouldcomprise approximately 10% copolymer by volume. In at least oneembodiment, the polymeric composition may comprise approximately 65% byweight of PGA and approximately 35% by weight of PCL, for example, andcan have a percent porosity from approximately 93% by volume toapproximately 95% by volume, for example. In various embodiments, thepolymeric composition may comprise greater than 85% porosity by volume.The polymeric composition may have a pore size from approximately 5micrometers to approximately 2000 micrometers, for example. In variousembodiments, the polymeric composition may have a pore size betweenapproximately 10 micrometers to approximately 100 micrometers, forexample. In at least one such embodiment, the polymeric composition cancomprise a copolymer of PGA and PCL, for example. In certainembodiments, the polymeric composition may have a pore size betweenapproximately 100 micrometers to approximately 1000 micrometers, forexample. In at least one such embodiment, the polymeric composition cancomprise a copolymer of PLLA and PCL, for example.

According to certain aspects, the hardness of a polymeric compositionmay be expressed in terms of the Shore Hardness, which can defined asthe resistance to permanent indentation of a material as determined witha durometer, such as a Shore Durometer. In order to assess the durometervalue for a given material, a pressure is applied to the material with adurometer indenter foot in accordance with ASTM procedure D2240-00,entitled, “Standard Test Method for Rubber Property-Durometer Hardness”,the entirety of which is incorporated herein by reference. The durometerindenter foot may be applied to the material for a sufficient period oftime, such as 15 seconds, for example, wherein a reading is then takenfrom the appropriate scale. Depending on the type of scale being used, areading of 0 can be obtained when the indenter foot completelypenetrates the material, and a reading of 100 can be obtained when nopenetration into the material occurs. This reading is dimensionless. Invarious embodiments, the durometer may be determined in accordance withany suitable scale, such as Type A and/or Type OO scales, for example,in accordance with ASTM D2240-00. In various embodiments, the polymericcomposition of a tissue thickness compensator may have a Shore Ahardness value from approximately 4 A to approximately 16 A, forexample, which is approximately 45 OO to approximately 65 OO on theShore OO range. In at least one such embodiment, the polymericcomposition can comprise a PLLA/PCL copolymer or a PGA/PCL copolymer,for example. In various embodiments, the polymeric composition of atissue thickness compensator may have a Shore A Hardness value of lessthan 15 A. In various embodiments, the polymeric composition of a tissuethickness compensator may have a Shore A Hardness value of less than 10A. In various embodiments, the polymeric composition of a tissuethickness compensator may have a Shore A Hardness value of less than 5A. In certain embodiments, the polymeric material may have a Shore OOcomposition value from approximately 35 OO to approximately 75 OO, forexample.

In various embodiments, the polymeric composition may have at least twoof the above-identified properties. In various embodiments, thepolymeric composition may have at least three of the above-identifiedproperties. The polymeric composition may have a porosity from 85% to97% by volume, a pore size from 5 micrometers to 2000 micrometers, and aShore A hardness value from 4 A to 16 A and Shore OO hardness value from45 OO to 65 OO, for example. In at least one embodiment, the polymericcomposition may comprise 70% by weight of the polymeric composition ofPLLA and 30% by weight of the polymeric composition of PCL having aporosity of 90% by volume, a pore size from 100 micrometers to 1000micrometers, and a Shore A hardness value from 4 A to 16 A and Shore OOhardness value from 45 OO to 65 OO, for example. In at least oneembodiment, the polymeric composition may comprise 65% by weight of thepolymeric composition of PGA and 35% by weight of the polymericcomposition of PCL having a porosity from 93% to 95% by volume, a poresize from 10 micrometers to 100 micrometers, and a Shore A hardnessvalue from 4 A to 16 A and Shore OO hardness value from 45 OO to 65 OO,for example.

In various embodiments, the tissue thickness compensator may comprise amaterial that expands. As discussed above, the tissue thicknesscompensator may comprise a compressed material that expands whenuncompressed or deployed, for example. In various embodiments, thetissue thickness compensator may comprise a self-expanding materialformed in situ. In various embodiments, the tissue thickness compensatormay comprise at least one precursor selected to spontaneously crosslinkwhen contacted with at least one of other precursor(s), water, and/orbodily fluids. Referring to FIG. 205, in various embodiments, a firstprecursor may contact one or more other precursors to form an expandableand/or swellable tissue thickness compensator. In various embodiments,the tissue thickness compensator may comprise a fluid-swellablecomposition, such as a water-swellable composition, for example. Invarious embodiments, the tissue thickness compensator may comprise a gelcomprising water.

Referring to FIGS. 189A and B, for example, a tissue thicknesscompensator 70000 may comprise at least one hydrogel precursor 70010selected to form a hydrogel in situ and/or in vivo to expand the tissuethickness compensator 70000. FIG. 189A illustrates a tissue thicknesscompensator 70000 comprising an encapsulation comprising a firsthydrogel precursor 70010A and a second hydrogel precursor 70010B priorto expansion. In certain embodiments, as shown in FIG. 189A, the firsthydrogel precursor 70010A and second hydrogel precursor 70010B may bephysically separated from other in the same encapsulation. In certainembodiments, a first encapsulation may comprise the first hydrogelprecursor 70010A and a second encapsulation may comprise the secondhydrogel precursor 70010B. FIG. 189B illustrates the expansion of thethickness tissue compensator 70000 when the hydrogel is formed in situand/or in vivo. As shown in FIG. 189B, the encapsulation may beruptured, and the first hydrogel precursor 70010A may contact the secondhydrogel precursor 70010B to form the hydrogel 70020. In certainembodiments, the hydrogel may comprise an expandable material. Incertain embodiments, the hydrogel may expand up to 72 hours, forexample.

In various embodiments, the tissue thickness compensator may comprise abiodegradable foam having an encapsulation comprising dry hydrogelparticles or granules embedded therein. Without wishing to be bound toany particular theory, the encapsulations in the foam may be formed bycontacting an aqueous solution of a hydrogel precursor and an organicsolution of biocompatible materials to form the foam. As shown in FIG.206, the aqueous solution and organic solution may form micelles. Theaqueous solution and organic solution may be dried to encapsulate dryhydrogel particles or granules within the foam. For example, a hydrogelprecursor, such as a hydrophilic polymer, may be dissolved in water toform a dispersion of micelles. The aqueous solution may contact anorganic solution of dioxane comprising poly(glycolic acid) andpolycaprolactone. The aqueous and organic solutions may be lyophilizedto form a biodegradable foam having dry hydrogel particles or granulesdispersed therein. Without wishing to be bound to any particular theory,it is believed that the micelles form the encapsulation having the dryhydrogel particles or granules dispersed within the foam structure. Incertain embodiments, the encapsulation may be ruptured, and the dryhydrogel particles or granules may contact a fluid, such as a bodilyfluid, and expand.

In various embodiments, the tissue thickness compensator may expand whencontacted with an activator, such as a fluid, for example. Referring toFIG. 190, for example, a tissue thickness compensator 70050 may comprisea swellable material, such as a hydrogel, that expands when contactedwith a fluid 70055, such as bodily fluids, saline, water and/or anactivator, for example. Examples of bodily fluids may include, but arenot limited to, blood, plasma, peritoneal fluid, cerebral spinal fluid,urine, lymph fluid, synovial fluid, vitreous fluid, saliva,gastrointestinal luminal contents, bile, and/or gas (e.g., CO₂). Incertain embodiments, the tissue thickness compensator 70050 may expandwhen the tissue thickness compensator 70050 absorbs the fluid. Inanother example, the tissue thickness compensator 70050 may comprise anon-crosslinked hydrogel that expands when contacted with an activator70055 comprising a cross-linking agent to form a crosslinked hydrogel.In various embodiments, the tissue thickness compensator may expand whencontacted with an activator. In various embodiments, the tissuethickness compensator may expand or swell from contact up to 72 hours,such as from 24-72 hours, up to 24 hours, up to 48 hours, and up to 72hours, for example, to provide continuously increasing pressure and/orcompression to the tissue. As shown in FIG. 190, the initial thicknessof the tissue thickness compensator 70050 may be less than an expandedthickness after the fluid 70055 contacts the tissue thicknesscompensator 70050.

Referring to FIGS. 187 and 188, in various embodiments, a staplecartridge 70100 may comprise a tissue thickness compensator 70105 and aplurality of staples 70110 each comprising staple legs 70112. As shownin FIG. 187, tissue thickness compensator 70105 may have an initialthickness or compressed height that is less than the fired height of thestaples 70110. The tissue thickness compensator 70100 may be configuredto expand in situ and/or in vivo when contacted with a fluid 70102, suchas bodily fluids, saline, and/or an activator for example, to push thetissue T against the legs 70112 of the staple 70110. As shown in FIG.188, the tissue thickness compensator 70100 may expand and/or swell whencontacted with a fluid 70102. The tissue thickness compensator 70105 cancompensate for the thickness of the tissue T captured within each staple70110. As shown in FIG. 188, tissue thickness compensator 70105 may havean expanded thickness or an uncompressed height that is less than thefired height of the staples 70110.

In various embodiments, as described above, the tissue thicknesscompensator may comprise an initial thickness and an expanded thickness.In certain embodiments, the initial thickness of a tissue thicknesscompensator can be approximately 0.001% of its expanded thickness,approximately 0.01% of its expanded thickness, approximately 0.1% of itsexpanded thickness, approximately 1% of its expanded thickness,approximately 10% of its expanded thickness, approximately 20% of itsexpanded thickness, approximately 30% of its expanded thickness,approximately 40% of its expanded thickness, approximately 50% of itsexpanded thickness, approximately 60% of its expanded thickness,approximately 70% of its expanded thickness, approximately 80% of itsexpanded thickness, and/or approximately 90% of its expanded thickness,for example. In various embodiments, the expanded thickness of thetissue thickness compensator can be approximately two times,approximately five times, approximately ten times, approximately fiftytimes, approximately one hundred times, approximately two hundred times,approximately three hundred times, approximately four hundred times,approximately five hundred times, approximately six hundred times,approximately seven hundred times, approximately eight hundred times,approximately nine hundred times, and/or approximately one thousandtimes thicker than its initial thickness, for example. In variousembodiments, the initial thickness of the tissue thickness compensatorcan be up to 1% its expanded thickness, up to 5% its expanded thickness,up to 10% its expanded thickness, and up to 50% its expanded thickness.In various embodiments, the expanded thickness of the tissue thicknesscompensator can be at least 50% thicker than its initial thickness, atleast 100% thicker than its initial thickness, at least 300% thickerthan its initial thickness, and at least 500% thicker than its initialthickness. As described above, in various circumstances, as a result ofthe above, the tissue thickness compensator can be configured to consumeany gaps within the staple entrapment area.

As discussed above, in various embodiments, the tissue thicknesscompensator may comprise a hydrogel. In various embodiments, thehydrogel may comprise homopolymer hydrogels, copolymer hydrogels,multipolymer hydrogels, interpenetrating polymer hydrogels, andcombinations thereof. In various embodiments, the hydrogel may comprisemicrogels, nanogels, and combinations thereof. The hydrogel maygenerally comprise a hydrophilic polymer network capable of absorbingand/or retaining fluids. In various embodiments, the hydrogel maycomprise a non-crosslinked hydrogel, a crosslinked hydrogel, andcombinations thereof. The hydrogel may comprise chemical crosslinks,physical crosslinks, hydrophobic segments and/or water insolublesegments. The hydrogel may be chemically crosslinked by polymerization,small-molecule crosslinking, and/or polymer-polymer crosslinking. Thehydrogel may be physically crosslinked by ionic interactions,hydrophobic interactions, hydrogen bonding interactions,sterocomplexation, and/or supramolecular chemistry. The hydrogel may besubstantially insoluble due to the crosslinks, hydrophobic segmentsand/or water insoluble segments, but be expandable and/or swellable dueto absorbing and/or retaining fluids. In certain embodiments, theprecursor may crosslink with endogenous materials and/or tissues.

In various embodiments, the hydrogel may comprise an environmentallysensitive hydrogel (ESH). The ESH may comprise materials havingfluid-swelling properties that relate to environmental conditions. Theenvironmental conditions may include, but are not limited to, thephysical conditions, biological conditions, and/or chemical conditionsat the surgical site. In various embodiments, the hydrogel may swell orshrink in response to temperature, pH, electric fields, ionic strength,enzymatic and/or chemical reactions, electrical and/or magnetic stimuli,and other physiological and environmental variables, for example. Invarious embodiments, the ESH may comprise multifunctional acrylates,hydroxyethylmethacrylate (HEMA), elastomeric acrylates, and relatedmonomers.

In various embodiments, the tissue thickness compensator comprising ahydrogel may comprise at least one of the non-synthetic materials andsynthetic materials described above. The hydrogel may comprise asynthetic hydrogel and/or a non-synthetic hydrogel. In variousembodiments, the tissue thickness compensator may comprise a pluralityof layers. The plurality of the layers may comprise porous layers and/ornon-porous layers. For example, the tissue thickness compensator maycomprise a non-porous layer and a porous layer. In another example, thetissue thickness compensator may comprise a porous layer intermediate afirst non-porous layer and a second non-porous layer. In anotherexample, the tissue thickness compensator may comprise a non-porouslayer intermediate a first porous layer and a second porous layer. Thenon-porous layers and porous layers may be positioned in any orderrelative to the surfaces of the staple cartridge and/or anvil.

Examples of the non-synthetic material may include, but are not limitedto, albumin, alginate, carbohydrate, casein, cellulose, chitin,chitosan, collagen, blood, dextran, elastin, fibrin, fibrinogen,gelatin, heparin, hyaluronic acid, keratin, protein, serum, and starch.The cellulose may comprise hydroxyethyl cellulose, oxidized cellulose,oxidized regenerated cellulose (ORC), hydroxypropyl cellulose,carboxyethyl cellulose, carboxymethylcellulose, and combinationsthereof. The collagen may comprise bovine pericardium. The carbohydratemay comprise a polysaccharide, such as lyophilized polysaccharide. Theprotein may comprise glycoprotein, proteoglycan, and combinationsthereof.

Examples of the synthetic material may include, but are not limited to,poly(lactic acid), poly(glycolic acid), poly(hydroxybutyrate),poly(phosphazine), polyesters, polyethylene glycols, polyethylene oxide,polyethylene oxide-co-polypropylene oxide, co-polyethylene oxide,polyalkyleneoxides, polyacrylamides, polyhydroxyethylmethylacrylate,poly(vinylpyrrolidone), polyvinyl alcohols, poly(caprolactone),poly(dioxanone), polyacrylic acid, polyacetate, polypropylene, aliphaticpolyesters, glycerols, poly(amino acids), copoly(ether-esters),polyalkylene oxalates, polyamides, poly(iminocarbonates), polyoxaesters,polyorthoesters, polyphosphazenes and combinations thereof. In certainembodiments, the above non-synthetic materials may be syntheticallyprepared, e.g., synthetic hyaluronic acid, utilizing conventionalmethods.

In various embodiments, the hydrogel may be made from one or morehydrogel precursors. The precursor may comprise a monomer and/or amacromer. The hydrogel precursor may comprise an electrophile functionalgroup and/or a nucleophile electrophile functional group. In general,electrophiles may react with nucleophiles to form a bond. The term“functional group” as used herein refers to electrophilic ornucleophilic groups capable of reacting with each other to form a bond.Examples of electrophilic functional groups may include, but are notlimited to, N-hydroxysuccinimides (“NHS”), sulfosuccinimides,carbonyldiimidazole, sulfonyl chloride, aryl halides, sulfosuccinimidylesters, N-hydroxysuccinimidyl esters, succinimidyl esters such assuccinimidyl succinates and/or succinimidyl propionates, isocyanates,thiocyanates, carbodiimides, benzotriazole carbonates, epoxides,aldehydes, maleimides, imidoesters, combinations thereof, and the like.In at least one embodiment, the electrophilic functional group maycomprise a succinimidyl ester. Examples of nucleophile functional groupsmay include, but are not limited to, —NH₂, —SH, —OH, —PH₂, and—CO—NH—NH₂.

In various embodiments, the hydrogel may be formed from a singleprecursor or multiple precursors. In certain embodiments, the hydrogelmay be formed from a first precursor and a second precursor. The firsthydrogel precursor and second hydrogel precursor may form a hydrogel insitu and/or in vivo upon contact. The hydrogel precursor may generallyrefer to a polymer, functional group, macromolecule, small molecule,and/or crosslinker that can take part in a reaction to form a hydrogel.The precursor may comprise a homogeneous solution, heterogeneous, orphase separated solution in a suitable solvent, such as water or abuffer, for example. The buffer may have a pH from about 8 to about 12,such as, about 8.2 to about 9, for example. Examples of buffers mayinclude, but are not limited to borate buffers. In certain embodiments,the precursor(s) may be in an emulsion. In various embodiments, a firstprecursor may react with a second precursor to form a hydrogel. Invarious embodiments, the first precursor may spontaneously crosslinkwhen contacted with the second precursor. In various embodiments, afirst set of electrophilic functional groups on a first precursor mayreact with a second set of nucleophilic functional groups on a secondprecursor. When the precursors are mixed in an environment that permitsreaction (e.g., as relating to pH, temperature, and/or solvent), thefunctional groups may react with each other to form covalent bonds. Theprecursors may become crosslinked when at least some of the precursorsreact with more than one other precursor.

In various embodiments, the tissue thickness compensator may comprise atleast one monomer selected from the group consisting of 3-sulfopropylacrylate potassium salt (“KSPA”), sodium acrylate (“NaA”),N-(tris(hydroxylmethyl)methyl)acrylamide (“tris acryl”), and2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS). The tissuethickness compensator may comprise a copolymer comprising two or moremonomers selected from the group consisting of KSPA, NaA, tris acryl,AMPS. The tissue thickness compensator may comprise homopolymers derivedfrom KSPA, NaA, trisacryl and AMPS. The tissue thickness compensator maycomprise hydrophilicity modifying monomers copolymerizable therewith.The hydrophilicity modifying monomers may comprise methylmethacrylate,butylacrylate, cyclohexylacrylate, styrene, styrene sulphonic acid.

In various embodiments, the tissue thickness compensator may comprise acrosslinker. The crosslinker may comprise a low molecular weight di- orpolyvinylic crosslinking agent, such as ethylenglycol diacrylate ordimethacrylate, di-, tri- or tetraethylen-glycol diacrylate ordimethacrylate, allyl(meth)acrylate, a C₂-C₈-alkylene diacrylate ordimethacrylate, divinyl ether, divinyl sulfone, di- and trivinylbenzene,trimethylolpropane triacrylate or trimethacrylate, pentaerythritoltetraacrylate or tetramethacrylate, bisphenol A diacrylate ordimethacrylate, methylene bisacrylamide or bismethacrylamide, ethylenebisacrylamide or ethylene bismethacrylamide, triallyl phthalate ordiallyl phthalate. In at least one embodiment, the crosslinker maycomprise N,N′-methylenebisacrylamide (“MBAA”).

In various embodiments, the tissue thickness compensator may comprise atleast one of acrylate and/or methacrylate functional hydrogels,biocompatible photoinitiator, alkyl-cyanoacrylates, isocyanatefunctional macromers, optionally comprising amine functional macromers,succinimidyl ester functional macromers, optionally comprising amineand/or sulfhydryl functional macromers, epoxy functional macromers,optionally comprising amine functional macromers, mixtures of proteinsand/or polypeptides and aldehyde crosslinkers, Genipin, andwater-soluble carbodiimides, anionic polysaccharides and polyvalentcations.

In various embodiments, the tissue thickness compensator may compriseunsaturated organic acid monomers, acrylic substituted alcohols, and/oracrylamides. In various embodiments, the tissue thickness compensatormay comprise methacrylic acids, acrylic acids, glycerolacrylate,glycerolmethacryulate, 2-hydroxyethylmethacrylate,2-hydroxyethylacrylate, 2-(dimethylaminoethyl)methacrylate, N-vinylpyrrolidone, methacrylamide, and/or N,N-dimethylacrylamidepoly(methacrylic acid).

In various embodiments, the tissue thickness compensator may comprise areinforcement material. In various embodiments, the reinforcementmaterial may comprise at least one of the non-synthetic materials andsynthetic materials described above. In various embodiments, thereinforcement material may comprise collagen, gelatin, fibrin,fibrinogen, elastin, keratin, albumin, hydroxyethyl cellulose,cellulose, oxidized cellulose, hydroxypropyl cellulose, carboxyethylcellulose, carboxymethylcellulose, chitan, chitosan, alginate,poly(lactic acid), poly(glycolic acid), poly(hydroxybutyrate),poly(phosphazine), polyesters, polyethylene glycols, polyalkyleneoxides,polyacrylamides, polyhydroxyethylmethylacrylate, polyvinylpyrrolidone,polyvinyl alcohols, poly(caprolactone), poly(dioxanone), polyacrylicacid, polyacetate, polycaprolactone, polypropylene, aliphaticpolyesters, glycerols, poly(amino acids), copoly(ether-esters),polyalkylene oxalates, polyamides, poly(iminocarbonates), polyalkyleneoxalates, polyoxaesters, polyorthoesters, polyphosphazenes andcombinations thereof.

In various embodiments, the tissue thickness compensator may comprise alayer comprising the reinforcement material. In certain embodiments, aporous layer and/or a non-porous layer of a tissue thickness compensatormay comprise the reinforcement material. For example, the porous layermay comprise the reinforcement material and the non-porous layer may notcomprise the reinforcement material. In various embodiments, thereinforcement layer may comprise an inner layer intermediate a firstnon-porous layer and a second non-porous layer. In certain embodiments,the reinforcement layer may comprise an outer layer of the tissuethickness compensator. In certain embodiments, the reinforcement layermay comprise an exterior surface of the tissue thickness compensator.

In various embodiments, the reinforcement material may comprise meshes,monofilaments, multifilament braids, fibers, mats, felts, particles,and/or powders. In certain embodiments, the reinforcement material maybe incorporated into a layer of the tissue thickness compensator. Thereinforcement material may be incorporated into at least one of anon-porous layer and a porous layer. A mesh comprising the reinforcementmaterial may be formed using conventional techniques, such as, forexample, knitting, weaving, tatting, and/or knipling. In variousembodiments, a plurality of reinforcement materials may be oriented in arandom direction and/or a common direction. In certain embodiments, thecommon direction may be one of parallel to the staple line andperpendicular to the staple line, for example. For example, themonofilaments and/or multifilament braids may be oriented in a randomdirection and/or a common direction. The monofilaments and multifilamentbraids may be associated with the non-porous layer and/or the porouslayer. In various embodiments, the tissue thickness compensator maycomprise a plurality of reinforcement fibers oriented in a randomdirection within a non-porous layer. In various embodiments, the tissuethickness compensator may comprise a plurality of reinforcement fibersoriented in a common direction within a non-porous layer.

In various embodiments, referring to FIG. 199, an anvil 70300 maycomprise a tissue thickness compensator 70305 comprising a firstnon-porous layer 70307 and a second non-porous layer 70309 sealinglyenclosing a reinforcement layer 70310. In various embodiments, thereinforcement layer 70310 may comprise a hydrogel comprising ORCparticles or fibers embedded therein, and the non-porous layers maycomprise ORC. As shown in FIG. 199, the tissue thickness compensator70305 may be configured to conform to the contour of the anvil 70300.The inner layer of the tissue thickness compensator 70305 may conform tothe inner surface of the anvil 70300, which includes the forming pockets70301.

The fibers may form a non-woven material, such as, for example, a matand a felt. The fibers may have any suitable length, such as, forexample from 0.1 mm to 100 mm and 0.4 mm to 50 mm. The reinforcementmaterial may be ground to a powder. The powder may have a particle sizefrom 10 micrometers to 1 cm, for example. The powder may be incorporatedinto the tissue thickness compensator.

In various embodiments, the tissue thickness compensator may be formedin situ. In various embodiments, the hydrogel may be formed in situ. Thetissue thickness compensator may be formed in situ by covalent, ionic,and/or hydrophobic bonds. Physical (non-covalent) crosslinks may resultfrom complexation, hydrogen bonding, desolvation, Van der Waalsinteractions, ionic bonding, and combinations thereof. Chemical(covalent) crosslinking may be accomplished by any of a number ofmechanisms, including: free radical polymerization, condensationpolymerization, anionic or cationic polymerization, step growthpolymerization, electrophile-nucleophile reactions, and combinationsthereof.

In various embodiments, in situ formation of the tissue thicknesscompensator may comprise reacting two or more precursors that arephysically separated until contacted in situ and/or react to anenvironmental condition to react with each other to form the hydrogel.In situ polymerizable polymers may be prepared from precursor(s) thatcan be reacted to form a polymer at the surgical site. The tissuethickness compensator may be formed by crosslinking reactions of theprecursor(s) in situ. In certain embodiments, the precursor may comprisean initiator capable of initiating a polymerization reaction for theformation of the in situ tissue thickness compensator. The tissuethickness compensator may comprise a precursor that can be activated atthe time of application to create, in various embodiments, a crosslinkedhydrogel. In situ formation of the tissue thickness compensator maycomprise activating at least one precursor to form bonds to form thetissue thickness compensator. In various embodiments, activation may beachieved by changes in the physical conditions, biological conditions,and/or chemical conditions at the surgical site, including, but notlimited to temperature, pH, electric fields, ionic strength, enzymaticand/or chemical reactions, electrical and/or magnetic stimuli, and otherphysiological and environmental variables. In various embodiments, theprecursors may be contacted outside the body and introduced to thesurgical site.

In various embodiments, the tissue thickness compensator may compriseone or more encapsulations, or cells, which can be configured to storeat least one component therein. In certain embodiments, theencapsulation may be configured to store a hydrogel precursor therein.In certain embodiments, the encapsulation may be configured to store twocomponents therein, for example. In certain embodiments, theencapsulation may be configured to store a first hydrogel precursor anda second hydrogel precursor therein. In certain embodiments, a firstencapsulation may be configured to store a first hydrogel precursortherein and a second encapsulation may be configured to store a secondhydrogel precursor therein. As described above, the encapsulations canbe aligned, or at least substantially aligned, with the staple legs topuncture and/or otherwise rupture the encapsulations when the staplelegs contact the encapsulation. In certain embodiments, theencapsulations may be compressed, crushed, collapsed, and/or otherwiseruptured when the staples are deployed. After the encapsulations havebeen ruptured, the component(s) stored therein can flow out of theencapsulation. The component stored therein may contact othercomponents, layers of the tissue thickness compensator, and/or thetissue. In various embodiments, the other components may be flowing fromthe same or different encapsulations, provided in the layers of thetissue thickness compensator, and/or provided to the surgical site bythe clinician. As a result of the above, the component(s) stored withinthe encapsulations can provide expansion and/or swelling of the tissuethickness compensator.

In various embodiments, the tissue thickness compensator may comprise alayer comprising the encapsulations. In various embodiments, theencapsulation may comprise a void, a pocket, a dome, a tube, andcombinations thereof associated with the layer. In certain embodiments,the encapsulations may comprise voids in the layer. In at least oneembodiment, the layer can comprise two layers that can be attached toone another wherein the encapsulations can be defined between the twolayers. In certain embodiments, the encapsulations may comprise domes onthe surface of the layer. For example, at least a portion of theencapsulations can be positioned within domes extending upwardly fromthe layer. In certain embodiments, the encapsulations may comprisepockets formed within the layer. In certain embodiments, a first portionof the encapsulations may comprise a dome and a second portion of theencapsulations may comprise a pocket. In certain embodiments, theencapsulations may comprise a tube embedded within the layer. In certainembodiments, the tube may comprise the non-synthetic materials and/orsynthetic materials described herein, such as PLA. In at least oneembodiment, the tissue thickness compensator may comprise a bioabsorablefoam, such as ORC, comprising PLA tubes embedded therein, and the tubemay encapsulate a hydrogel, for example. In certain embodiments, theencapsulations may comprise discrete cells that are unconnected to eachother. In certain embodiments, one or more of the encapsulations can bein fluid communication with each other via one or more passageways,conduits, and/or channels, for example, extending through the layer.

The rate of release of a component from the encapsulation may becontrolled by the thickness of the tissue thickness compensator, thecomposition of tissue thickness compensator, the size of the component,the hydrophilicity of the component, and/or the physical and/or chemicalinteractions among the component, the composition of the tissuethickness compensator, and/or the surgical instrument, for example. Invarious embodiments, the layer can comprise one or more thin sections orweakened portions, such as partial perforations, for example, which canfacilitate the incision of the layer and the rupture of theencapsulations. In various embodiments, the partial perforations may notcompletely extend through a layer while, in certain embodiments,perforations may completely extend through the layer.

Referring to FIGS. 194 and 195, in various embodiments, a tissuethickness compensator 70150 may comprise an outer layer 70152A and aninner layer 70152B comprising encapsulations 70154. In certainembodiments, the encapsulation may comprise a first encapsulatedcomponent and a second encapsulated component. In certain embodiments,the encapsulations may independently comprise one of a firstencapsulated component and a second encapsulated component. The firstencapsulated component may be separated from the second encapsulatedcomponent. The outer layer 70152A may comprise a tissue-contactingsurface. The inner layer 70152B may comprise an instrument-contactingsurface. The instrument-contacting surface 70152B may be releasablyattached to the anvil 70156. The outer layer 70152A may be attached tothe inner layer 70152B to define a void between the outer layer 70152Aand inner layer 70152B. As shown in FIG. 194, each encapsulation 70154may comprise a dome on the instrument-contacting surface of the innerlayer 70152B. The dome may comprise partial perforations to facilitatethe incision of the layer by the staple legs and the rupture of theencapsulation. As shown in the FIG. 195, the anvil 70156 can comprise aplurality of forming pocket rows 70158 wherein the domes of theencapsulations 70154 may be aligned with the forming pocket 70158. Thetissue-contacting surface may comprise a flat surface lacking domes. Incertain embodiments, the tissue-contacting surface may comprise one ormore encapsulations, such as encapsulations 70154, for example,extending therefrom.

In various embodiments, an anvil may comprise a tissue thicknesscompensator comprising an encapsulated component comprising at least onemicrosphere particle. In certain embodiments, the tissue thicknesscompensator may comprise an encapsulation comprising a firstencapsulated component and a second encapsulated component. In certainembodiments, the tissue thickness compensator may comprise anencapsulation comprising a first microsphere particle and a secondmicrosphere particle.

In various embodiments, referring to FIG. 196, a stapling apparatus maycomprise an anvil 70180 and a staple cartridge (illustrated in otherfigures). The staples 70190 of a staple cartridge can be deformed by ananvil 70180 when the anvil 70180 is moved into a closed position and/orby a staple driver system 70192 which moves the staples 70190 toward theclosed anvil 70180. The legs 70194 of the staples may contact the anvil70180 such that the staples 70190 are at least partially deformed. Theanvil 70180 may comprise a tissue thickness compensator 70182 comprisingan outer layer 70183A, an inner layer 70183B. The tissue thicknesscompensator 70182 may comprise a first encapsulated component and asecond encapsulated component. In certain embodiments, theencapsulations 210185 can be aligned, or at least substantially aligned,such that, when the staple legs 70194 are pushed through the tissue Tand the outer layer 70183A, the staple legs 70194 can puncture and/orotherwise rupture the encapsulations 70185. As shown in FIG. 196, thestaple 70190C is in its fully fired position, the staple 70190B is inthe process of being fired, and the staple 70190A is in its unfiredposition. The legs of staples 70190C and 70190B have moved through thetissue T, the outer layer 70183A, and the inner layer 70183B of thetissue thickness compensator 70182, and have contacted an anvil 70180positioned opposite the staple cartridge. After the encapsulations 70185have been ruptured, the encapsulated components can flow out and contacteach other, bodily fluids, and/or the tissue T, for example. Theencapsulated components may react to form a reaction product such as ahydrogel, for example, to expand between the tissue T and the base ofthe staple and to push the tissue T against the legs of the staple. Invarious circumstances, as a result of the above, the tissue thicknesscompensator can be configured to consume any gaps within the stapleentrapment area.

In various embodiments, the tissue thickness compensator may be suitablefor use with a surgical instrument. As described above the tissuethickness compensator may be associated with the staple cartridge and/orthe anvil. The tissue thickness compensator may be configured into anyshape, size and/or dimension suitable to fit the staple cartridge and/oranvil. As described herein, the tissue thickness compensator may bereleasably attached to the staple cartridge and/or anvil. The tissuethickness compensator may be attached to the staple cartridge and/oranvil in any mechanical and/or chemical manner capable of retaining thetissue thickness compensator in contact with the staple cartridge and/oranvil prior to and during the stapling process. The tissue thicknesscompensator may be removed or released from the staple cartridge and/oranvil after the staple penetrates the tissue thickness compensator. Thetissue thickness compensator may be removed or released from the staplecartridge and/or anvil as the staple cartridge and/or anvil is movedaway from the tissue thickness compensator.

Referring to FIGS. 191-193, stapling apparatus 70118 may comprise ananvil 70120 and a staple cartridge 70122 comprising a firing member70124, a plurality of staples 70128, a knife edge 70129, and a tissuethickness compensator 70130. The tissue thickness compensator 70130 maycomprise at least one encapsulated component. The encapsulated componentmay be ruptured when the tissue thickness compensator is compressed,stapled, and/or cut. Referring to FIG. 192, for example, the staples70128 can be deployed between an unfired position and a fired positionsuch that the staple legs move through the tissue thickness compensator70130, penetrate through a bottom surface and a top surface of thetissue thickness compensator 70130, penetrate the tissue T, and contactan anvil 70120 positioned opposite the staple cartridge 70118. Theencapsulated components may react with each other, a hydrophilic powderembedded or dispersed in the tissue thickness compensator, and/or bodilyfluids to expand or swell the tissue thickness compensator 70130. As thelegs are deformed against the anvil, the legs of each staple can capturea portion of the tissue thickness compensator 70130 and a portion of thetissue T within each staple 70128 and apply a compressive force to thetissue T. As shown in FIGS. 192 and 193, the tissue thicknesscompensator 70130 can compensate for the thickness of the tissue Tcaptured within each staple 70128.

Referring to FIG. 197, a surgical instrument 70200 may comprise an anvil70205 comprising an upper tissue thickness compensator 70210 and astaple cartridge 70215 comprising a lower tissue thickness compensatorcomprising an outer layer 70220 and an inner layer 70225. The uppertissue thickness compensator 70210 can be positioned on a first side ofthe targeted tissue and the lower tissue thickness compensator can bepositioned on a second side of the tissue. In certain embodiments, theupper tissue thickness compensator 70210 may comprise ORC, the outerlayer of the lower tissue thickness compensator may comprise a hydrogelhaving ORC particles embedded therein, and the inner layer of the lowertissue thickness compensator may comprise ORC, for example.

Referring to FIGS. 200-202, in various embodiments, a surgicalinstrument 70400 may comprise a staple cartridge 70405 and an anvil70410. The staple cartridge 70405 may comprise a tissue thicknesscompensator 70415 including bioabsorbable foam. In various embodiments,the bioabsorbable foam can comprise an encapsulation which comprises anencapsulated component 70420. The bioabsorable foam may comprise ORC andthe encapsulated component may comprise a medicament, for example. Thetissue thickness compensator 70415 of the anvil 70410 may comprise aninner layer 70425 and an outer layer 70430. The inner layer 70425 maycomprise a bioabsorbable foam, and the outer layer 70430 may comprise ahydrogel, optionally comprising reinforcement materials, for example.During an exemplary firing sequence, referring primarily to FIG. 201, asled 70435 can first contact staple 70440A and begin to lift the stapleupwardly. As the sled 70435 is advanced further distally, the sled 70435can begin to lift staples 70440B-D, and any other subsequent staples, ina sequential order. The sled 70435 can drive the staples 70440 upwardlysuch that the legs of the staples contact the opposing anvil 70410 andare deformed to a desired shape. With regard to the firing sequenceillustrated in FIG. 201, the staples 70440A-C have been moved into theirfully fired positions, the staple 70440D is in the process of beingfired, and the staple 70420E is still in its unfired position. Theencapsulated component 70470 may be ruptured by the staple legs duringthe exemplary firing sequence. The encapsulated component 70420 may flowfrom the encapsulation around the staple legs to contact the tissue T.In various circumstances, additional compression of the tissue thicknesscompensator can squeeze additional medicament out of the encapsulation.In various embodiments, the medicament can immediately treat the tissueand can reduce bleeding from the tissue.

In various circumstances, a surgeon, or other clinician, may deliver afluid to the tissue thickness compensator to manufacture a tissuethickness compensator comprising at least one medicament stored and/orabsorbed therein. In various embodiments, a staple cartridge and/oranvil may comprise a port configured to provide access to the tissuethickness compensator. Referring to FIG. 203B, a staple cartridge 70500may comprise a port 70505 at a distal end thereof, for example. The port70505 may be configured to receive a needle 70510, such as a fenestratedneedle shown in FIG. 203A. In at least one embodiment, the clinician mayinsert a needle 70510 through the port 70505 into the tissue thicknesscompensator 70515 to deliver the fluid to the tissue thicknesscompensator 70515. In various embodiments, the fluid may comprise amedicament and hydrogel precursor, for example. As described above, thefluid may be released from tissue thickness compensator to the tissuewhen the tissue thickness compensator is ruptured and/or compressed. Forexample, the medicament may be released from the tissue thicknesscompensator 70515 as the tissue thickness compensator 70515 biodegrades.

In various embodiments, referring now to FIG. 14, a staple cartridge,such as staple cartridge 10000, for example, can comprise a supportportion 10010 and a compressible tissue thickness compensator 10020.Referring now to FIGS. 16-18, the support portion 10010 can comprise adeck surface 10011 and a plurality of staple cavities 10012 definedwithin the support portion 10010. Each staple cavity 10012 can be sizedand configured to removably store a staple, such as a staple 10030, forexample, therein. The staple cartridge 10000 can further comprise aplurality of staple drivers 10040 which can each be configured tosupport one or more staples 10030 within the staple cavities 10012 whenthe staples 10030 and the staple drivers 10040 are in their unfiredpositions. In at least one such embodiment, referring primarily to FIGS.22 and 23, each staple driver 10040 can comprise one or more cradles, ortroughs, 10041, for example, which can be configured to support thestaples and limit relative movement between the staples 10030 and thestaple drivers 10040. In various embodiments, referring again to FIG.16, the staple cartridge 10000 can further comprise a staple-firing sled10050 which can be moved from a proximal end 10001 to a distal end 10002of the staple cartridge in order to sequentially lift the staple drivers10040 and the staples 10030 from their unfired positions toward an anvilpositioned opposite the staple cartridge 10000. In certain embodiments,referring primarily to FIGS. 16 and 18, each staple 10030 can comprise abase 10031 and one or more legs 10032 extending from the base 10031wherein each staple can be at least one of substantially U-shaped andsubstantially V-shaped, for example. In at least one embodiment, thestaples 10030 can be configured such that the tips of the staple legs10032 are recessed with respect to the deck surface 10011 of the supportportion 10010 when the staples 10030 are in their unfired positions. Inat least one embodiment, the staples 10030 can be configured such thatthe tips of the staple legs 10032 are flush with respect to the decksurface 10011 of the support portion 10010 when the staples 10030 are intheir unfired positions. In at least one embodiment, the staples 10030can be configured such that the tips of the staple legs 10032, or atleast some portion of the staple legs 10032, extend above the decksurface 10011 of the support portion 10010 when the staples 10030 are intheir unfired positions. In such embodiments, the staple legs 10032 canextend into and can be embedded within the tissue thickness compensator10020 when the staples 10030 are in their unfired positions. In at leastone such embodiment, the staple legs 10032 can extend above the decksurface 10011 by approximately 0.075″, for example. In variousembodiments, the staple legs 10032 can extend above the deck surface10011 by a distance between approximately 0.025″ and approximately0.125″, for example. In certain embodiments, further to the above, thetissue thickness compensator 10020 can comprise an uncompressedthickness between approximately 0.08″ and approximately 0.125″, forexample.

In use, further to the above and referring primarily to FIG. 31, ananvil, such as anvil, 10060, for example, can be moved into a closedposition opposite the staple cartridge 10000. As described in greaterdetail below, the anvil 10060 can position tissue against the tissuethickness compensator 10020 and, in various embodiments, compress thetissue thickness compensator 10020 against the deck surface 10011 of thesupport portion 10010, for example. Once the anvil 10060 has beensuitably positioned, the staples 10030 can be deployed, as alsoillustrated in FIG. 31. In various embodiments, as mentioned above, thestaple-firing sled 10050 can be moved from the proximal end 10001 of thestaple cartridge 10000 toward the distal end 10002, as illustrated inFIG. 32. As the sled 10050 is advanced, the sled 10050 can contact thestaple drivers 10040 and lift the staple drivers 10040 upwardly withinthe staple cavities 10012. In at least one embodiment, the sled 10050and the staple drivers 10040 can each comprise one or more ramps, orinclined surfaces, which can co-operate to move the staple drivers 10040upwardly from their unfired positions. In at least one such embodiment,referring to FIGS. 19-23, each staple driver 10040 can comprise at leastone inclined surface 10042 and the sled 10050 can comprise one or moreinclined surfaces 10052 which can be configured such that the inclinedsurfaces 10052 can slide under the inclined surface 10042 as the sled10050 is advanced distally within the staple cartridge. As the stapledrivers 10040 are lifted upwardly within their respective staplecavities 10012, the staple drivers 10040 can lift the staples 10030upwardly such that the staples 10030 can emerge from their staplecavities 10012 through openings in the staple deck 10011. During anexemplary firing sequence, referring primarily to FIGS. 25-27, the sled10050 can first contact staple 10030 a and begin to lift the staple10030 a upwardly. As the sled 10050 is advanced further distally, thesled 10050 can begin to lift staples 10030 b, 10030 c, 10030 d, 10030 e,and 10030 f, and any other subsequent staples, in a sequential order. Asillustrated in FIG. 27, the sled 10050 can drive the staples 10030upwardly such that the legs 10032 of the staples contact the opposinganvil, are deformed to a desired shape, and ejected therefrom thesupport portion 10010. In various circumstances, the sled 10030 can moveseveral staples upwardly at the same time as part of a firing sequence.With regard to the firing sequence illustrated in FIG. 27, the staples10030 a and 10030 b have been moved into their fully fired positions andejected from the support portion 10010, the staples 10030 c and 10030 dare in the process of being fired and are at least partially containedwithin the support portion 10010, and the staples 10030 e and 10030 fare still in their unfired positions.

As discussed above, and referring to FIG. 33, the staple legs 10032 ofthe staples 10030 can extend above the deck surface 10011 of the supportportion 10010 when the staples 10030 are in their unfired positions.With further regard to this firing sequence illustrated in FIG. 27, thestaples 10030 e and 10030 f are illustrated in their unfired positionand their staple legs 10032 extend above the deck surface 10011 and intothe tissue thickness compensator 10020. In various embodiments, the tipsof the staple legs 10032, or any other portion of the staple legs 10032,may not protrude through a top tissue-contacting surface 10021 of thetissue thickness compensator 10020 when the staples 10030 are in theirunfired positions. As the staples 10030 are moved from their unfiredpositions to their fired positions, as illustrated in FIG. 27, the tipsof the staple legs can protrude through the tissue-contacting surface10032. In various embodiments, the tips of the staple legs 10032 cancomprise sharp tips which can incise and penetrate the tissue thicknesscompensator 10020. In certain embodiments, the tissue thicknesscompensator 10020 can comprise a plurality of apertures which can beconfigured to receive the staple legs 10032 and allow the staple legs10032 to slide relative to the tissue thickness compensator 10020. Incertain embodiments, the support portion 10010 can further comprise aplurality of guides 10013 extending from the deck surface 10011. Theguides 10013 can be positioned adjacent to the staple cavity openings inthe deck surface 10011 such that the staple legs 10032 can be at leastpartially supported by the guides 10013. In certain embodiments, a guide10013 can be positioned at a proximal end and/or a distal end of astaple cavity opening. In various embodiments, a first guide 10013 canbe positioned at a first end of each staple cavity opening and a secondguide 10013 can be positioned at a second end of each staple cavityopening such that each first guide 10013 can support a first staple leg10032 of a staple 10030 and each second guide 10013 can support a secondstaple leg 10032 of the staple. In at least one embodiment, referring toFIG. 33, each guide 10013 can comprise a groove or slot, such as groove10016, for example, within which a staple leg 10032 can be slidablyreceived. In various embodiments, each guide 10013 can comprise a cleat,protrusion, and/or spike that can extend from the deck surface 10011 andcan extend into the tissue thickness compensator 10020. In at least oneembodiment, as discussed in greater detail below, the cleats,protrusions, and/or spikes can reduce relative movement between thetissue thickness compensator 10020 and the support portion 10010. Incertain embodiments, the tips of the staple legs 10032 may be positionedwithin the guides 10013 and may not extend above the top surfaces of theguides 10013 when the staples 10030 are in their unfired position. In atleast such embodiment, the guides 10013 can define a guide height andthe staples 10030 may not extend above this guide height when they arein their unfired position.

In various embodiments, a tissue thickness compensator, such as tissuethickness compensator 10020, for example, can be comprised of a singlesheet of material. In at least one embodiment, a tissue thicknesscompensator can comprise a continuous sheet of material which can coverthe entire top deck surface 10011 of the support portion 10010 or,alternatively, cover less than the entire deck surface 10011. In certainembodiments, the sheet of material can cover the staple cavity openingsin the support portion 10010 while, in other embodiments, the sheet ofmaterial can comprise openings which can be aligned, or at leastpartially aligned, with the staple cavity openings. In variousembodiments, a tissue thickness compensator can be comprised of multiplelayers of material. In some embodiments, referring now to FIG. 15, atissue thickness compensator can comprise a compressible core and a wrapsurrounding the compressible core. In certain embodiments, a wrap 10022can be configured to releasably hold the compressible core to thesupport portion 10010. In at least one such embodiment, the supportportion 10010 can comprise one or more projections, such as projections10014 (FIG. 18), for example, extending therefrom which can be receivedwithin one or more apertures and/or slots, such as apertures 10024, forexample, defined in the wrap 10022. The projections 10014 and theapertures 10024 can be configured such that the projections 10014 canretain the wrap 10022 to the support portion 10010. In at least oneembodiment, the ends of the projections 10014 can be deformed, such asby a heat-stake process, for example, in order to enlarge the ends ofthe projections 10014 and, as a result, limit the relative movementbetween the wrap 10022 and the support portion 10010. In at least oneembodiment, the wrap 10022 can comprise one or more perforations 10025which can facilitate the release of the wrap 10022 from the supportportion 10010, as illustrated in FIG. 15. Referring now to FIG. 24, atissue thickness compensator can comprise a wrap 10222 including aplurality of apertures 10223, wherein the apertures 10223 can bealigned, or at least partially aligned, with the staple cavity openingsin the support portion 10010. In certain embodiments, the core of thetissue thickness compensator can also comprise apertures which arealigned, or at least partially aligned, with the apertures 10223 in thewrap 10222. In other embodiments, the core of the tissue thicknesscompensator can comprise a continuous body and can extend underneath theapertures 10223 such that the continuous body covers the staple cavityopenings in the deck surface 10011.

In various embodiments, as described above, a tissue thicknesscompensator can comprise a wrap for releasably holding a compressiblecore to the support portion 10010. In at least one such embodiment,referring to FIG. 16, a staple cartridge can further comprise retainerclips 10026 which can be configured to inhibit the wrap, and thecompressible core, from prematurely detaching from the support portion10010. In various embodiments, each retainer clip 10026 can compriseapertures 10028 which can be configured to receive the projections 10014extending from the support portion 10010 such that the retainer clips10026 can be retained to the support portion 10010. In certainembodiments, the retainer clips 10026 can each comprise at least one panportion 10027 which can extend underneath the support portion 10010 andcan support and retain the staple drivers 10040 within the supportportion 10010. In certain embodiments, as described above, a tissuethickness compensator can be removably attached to the support portion10010 by the staples 10030. More particularly, as also described above,the legs of the staples 10030 can extend into the tissue thicknesscompensator 10020 when the staples 10030 are in their unfired positionand, as a result, releasably hold the tissue thickness compensator 10020to the support portion 10010. In at least one embodiment, the legs ofthe staples 10030 can be in contact with the sidewalls of theirrespective staple cavities 10012 wherein, owing to friction between thestaple legs 10032 and the sidewalls, the staples 10030 and the tissuethickness compensator 10020 can be retained in position until thestaples 10030 are deployed from the staple cartridge 10000. When thestaples 10030 are deployed, the tissue thickness compensator 10020 canbe captured within the staples 10030 and held against the stapled tissueT. When the anvil is thereafter moved into an open position to releasethe tissue T, the support portion 10010 can be moved away from thetissue thickness compensator 10020 which has been fastened to thetissue. In certain embodiments, an adhesive can be utilized to removablyhold the tissue thickness compensator 10020 to the support portion10010. In at least one embodiment, a two-part adhesive can be utilizedwherein, in at least one embodiment, a first part of the adhesive can beplaced on the deck surface 10011 and a second part of the adhesive canbe placed on the tissue thickness compensator 10020 such that, when thetissue thickness compensator 10020 is placed against the deck surface10011, the first part can contact the second part to active the adhesiveand detachably bond the tissue thickness compensator 10020 to thesupport portion 10010. In various embodiments, any other suitable meanscould be used to detachably retain the tissue thickness compensator tothe support portion of a staple cartridge.

In various embodiments, further to the above, the sled 10050 can beadvanced from the proximal end 10001 to the distal end 10002 to fullydeploy all of the staples 10030 contained within the staple cartridge10000. In at least one embodiment, referring now to FIGS. 56-60, thesled 10050 can be advanced distally within a longitudinal cavity 10016within the support portion 10010 by a firing member, or knife bar, 10052of a surgical stapler. In use, the staple cartridge 10000 can beinserted into a staple cartridge channel in a jaw of the surgicalstapler, such as staple cartridge channel 10070, for example, and thefiring member 10052 can be advanced into contact with the sled 10050, asillustrated in FIG. 56. As the sled 10050 is advanced distally by thefiring member 10052, the sled 10050 can contact the proximal-most stapledriver, or drivers, 10040 and fire, or eject, the staples 10030 from thecartridge body 10010, as described above. As illustrated in FIG. 56, thefiring member 10052 can further comprise a cutting edge 10053 which canbe advanced distally through a knife slot in the support portion 10010as the staples 10030 are being fired. In various embodiments, acorresponding knife slot can extend through the anvil positionedopposite the staple cartridge 10000 such that, in at least oneembodiment, the cutting edge 10053 can extend between the anvil and thesupport portion 10010 and incise the tissue and the tissue thicknesscompensator positioned therebetween. In various circumstances, the sled10050 can be advanced distally by the firing member 10052 until the sled10050 reaches the distal end 10002 of the staple cartridge 10000, asillustrated in FIG. 58. At such point, the firing member 10052 can beretracted proximally. In some embodiments, the sled 10050 can beretracted proximally with the firing member 10052 but, in variousembodiments, referring now to FIG. 59, the sled 10050 can be left behindin the distal end 10002 of the staple cartridge 10000 when the firingmember 10052 is retracted. Once the firing member 10052 has beensufficiently retracted, the anvil can be re-opened, the tissue thicknesscompensator 10020 can be detached from the support portion 10010, andthe remaining non-implanted portion of the expended staple cartridge10000, including the support portion 10010, can be removed from thestaple cartridge channel 10070.

After the expended staple cartridge 10000 has been removed from thestaple cartridge channel, further to the above, a new staple cartridge10000, or any other suitable staple cartridge, can be inserted into thestaple cartridge channel 10070. In various embodiments, further to theabove, the staple cartridge channel 10070, the firing member 10052,and/or the staple cartridge 10000 can comprise co-operating featureswhich can prevent the firing member 10052 from being advanced distally asecond, or subsequent, time without a new, or unfired, staple cartridge10000 positioned in the staple cartridge channel 10070. Moreparticularly, referring again to FIG. 56, as the firing member 10052 isadvanced into contact with the sled 10050 and, when the sled 10050 is inits proximal unfired position, a support nose 10055 of the firing member10052 can be positioned on and/or over a support ledge 10056 on the sled10050 such that the firing member 10052 is held in a sufficient upwardposition to prevent a lock, or beam, 10054 extending from the firingmember 10052 from dropping into a lock recess defined within the staplecartridge channel. As the lock 10054 will not drop into the lock recess,in such circumstances, the lock 10054 may not abut a distal sidewall10057 of the lock recess as the firing member 10052 is advanced. As thefiring member 10052 pushes the sled 10050 distally, the firing member10052 can be supported in its upward firing position owing to thesupport nose 10055 resting on the support ledge 10056. When the firingmember 10052 is retracted relative to the sled 10050, as discussed aboveand illustrated in FIG. 59, the firing member 10052 can drop downwardlyfrom its upward position as the support nose 10055 is no longer restingon the support ledge 10056 of the sled 10050. In at least one suchembodiment, the surgical staple can comprise a spring 10058, and/or anyother suitable biasing element, which can be configured to bias thefiring member 10052 into its downward position. Once the firing member10052 has been completely retracted, as illustrated in FIG. 60, thefiring member 10052 cannot be advanced distally through the spent staplecartridge 10000 once again. More particularly, the firing member 10052can't be held in its upper position by the sled 10050 as the sled 10050,at this point in the operating sequence, has been left behind at thedistal end 10002 of the staple cartridge 10000. Thus, as mentionedabove, in the event that the firing member 10052 is advanced once againwithout replacing the staple cartridge, the lock beam 10054 will contactthe sidewall 10057 of the lock recess which will prevent the firingmember 10052 from being advanced distally into the staple cartridge10000 once again. Stated another way, once the spent staple cartridge10000 has been replaced with a new staple cartridge, the new staplecartridge will have a proximally-positioned sled 10050 which can holdthe firing member 10052 in its upper position and allow the firingmember 10052 to be advanced distally once again.

As described above, the sled 10050 can be configured to move the stapledrivers 10040 between a first, unfired position and a second, firedposition in order to eject staples 10030 from the support portion 10010.In various embodiments, the staple drivers 10040 can be contained withinthe staple cavities 10012 after the staples 10030 have been ejected fromthe support portion 10010. In certain embodiments, the support portion10010 can comprise one or more retention features which can beconfigured to block the staple drivers 10040 from being ejected from, orfalling out of, the staple cavities 10012. In various other embodiments,the sled 10050 can be configured to eject the staple drivers 10040 fromthe support portion 10010 with the staples 10030. In at least one suchembodiment, the staple drivers 10040 can be comprised of a bioabsorbableand/or biocompatible material, such as Ultem, for example. In certainembodiments, the staple drivers can be attached to the staples 10030. Inat least one such embodiment, a staple driver can be molded over and/oraround the base of each staple 10030 such that the driver is integrallyformed with the staple. U.S. patent application Ser. No. 11/541,123,entitled SURGICAL STAPLES HAVING COMPRESSIBLE OR CRUSHABLE MEMBERS FORSECURING TISSUE THEREIN AND STAPLING INSTRUMENTS FOR DEPLOYING THE SAME,filed on Sep. 29, 2006, is hereby incorporated by reference in itsentirety.

As described above, a surgical stapling instrument can comprise a staplecartridge channel configured to receive a staple cartridge, an anvilrotatably coupled to the staple cartridge channel, and a firing membercomprising a knife edge which is movable relative to the anvil and thestaple cartridge channel. In use, a staple cartridge can be positionedwithin the staple cartridge channel and, after the staple cartridge hasbeen at least partially expended, the staple cartridge can be removedfrom the staple cartridge channel and replaced with a new staplecartridge. In some such embodiments, the staple cartridge channel, theanvil, and/or the firing member of the surgical stapling instrument maybe re-used with the replacement staple cartridge. In certain otherembodiments, a staple cartridge may comprise a part of a disposableloading unit assembly which can include a staple cartridge channel, ananvil, and/or a firing member, for example, which can be replaced alongwith the staple cartridge as part of replacing the disposable loadingunit assembly. Certain disposable loading unit assemblies are disclosedin U.S. patent application Ser. No. 12/031,817, entitled END EFFECTORCOUPLING ARRANGEMENTS FOR A SURGICAL CUTTING AND STAPLING INSTRUMENT,now U.S. Patent Application Publication No. 2009/0206131, which wasfiled on Feb. 15, 2008, the entire disclosure of which is incorporatedby reference herein.

In various embodiments, the tissue thickness compensator may comprise anextrudable, a castable, and/or moldable composition comprising at leastone of the synthetic and/or non-synthetic materials described herein. Invarious embodiments, the tissue thickness compensator may comprise afilm or sheet comprising two or more layers. The tissue thicknesscompensator may be obtained using conventional methods, such as, forexample, mixing, blending, compounding, spraying, wicking, solventevaporating, dipping, brushing, vapor deposition, extruding,calendaring, casting, molding and the like. In extrusion, an opening maybe in the form of a die comprising at least one opening to impart ashape to the emerging extrudate. In calendering, an opening may comprisea nip between two rolls. Conventional molding methods may include, butare not limited to, blow molding, injection molding, foam injection,compression molding, thermoforming, extrusion, foam extrusion, filmblowing, calendaring, spinning, solvent welding, coating methods, suchas dip coating and spin coating, solution casting and film casting,plastisol processing (including knife coating, roller coating andcasting), and combinations thereof. In injection molding, an opening maycomprise a nozzle and/or channels/runners and/or mold cavities andfeatures. In compression molding, the composition may be positioned in amold cavity, heated to a suitable temperature, and shaped by exposure tocompression under relatively high pressure. In casting, the compositionmay comprise a liquid or slurry that may be poured or otherwise providedinto, onto and/or around a mold or object to replicate features of themold or object. After casting, the composition may be dried, cooled,and/or cured to form a solid.

In various embodiments, a method of manufacturing a tissue thicknesscompensator may generally comprise providing a tissue thicknesscompensator composition, liquifying the composition to make it flowable,and forming the composition in the molten, semi-molten, or plastic stateinto a layer and/or film having the desired thickness. Referring to FIG.198A, a tissue thickness compensator may be manufactured by dissolving ahydrogel precursor in an aqueous solution, dispersing biocompatibleparticles and/or fibers therein, providing a mold having biocompatibleparticles therein, providing the solution into the mold, contacting anactivator and the solution, and curing the solution to form the tissuethickness compensator comprising an outer layer comprise biocompatibleparticles and an inner layer comprising biocompatible particles embeddedtherein. A shown in FIG. 198A, a biocompatible layer 70250 may beprovided in the bottom of a mold 70260, and an aqueous solution of ahydrogel precursor 70255 having biocompatible particles 70257 disposedtherein may be provided to the mold 70260, and the aqueous solution maybe cured to form a tissue thickness compensator having a first layercomprising a biocompatible material, such as ORC, for example, and asecond layer comprising a hydrogel having biocompatible fibers, such asORC fibers, disposed therein. The tissue thickness compensator maycomprise a foam comprising an outer layer comprise biocompatibleparticles and an inner layer comprising biocompatible particles embeddedtherein. In at least one embodiment, a tissue thickness compensator maybe manufactured by dissolving a sodium alginater in water, dispersingORC particles therein, providing a mold having ORC particles therein,pouring the solution into the mold, spraying or infusing calciumchloride to contact the solution to initiate crosslinking of the sodiumalginater, freeze drying the hydrogel to form the tissue thicknesscompensator comprising an outer layer comprising ORC and an inner layercomprising a hydrogel and ORC particles embedded therein.

Referring to FIG. 198B, in various embodiments, a method ofmanufacturing a trilayer tissue thickness compensator may generallycomprise by dissolving a first hydrogel precursor in a first aqueoussolution, dispersing biocompatible particles and/or fibers in the firstaqueous solution, providing a mold 70260 having a first layer 70250 ofbiocompatible particles therein, providing the first aqueous solutioninto the mold, contacting an activator and the first aqueous solution,curing the first aqueous solution to form a second layer 70255,dissolving a second hydrogel precursor in a second aqueous solution,providing the second aqueous solution into the mold, curing the secondaqueous solution to form a third layer 70265. In at least oneembodiment, a trilayer tissue thickness compensator may be manufacturedby dissolving a sodium alginater in water to form a first aqueoussolution, dispersing ORC particles in the first aqueous solution,providing a mold having a first layer of ORC particles therein, pouringthe first aqueous solution into the mold, spraying or infusing calciumchloride to contact the first aqueous solution to initiate crosslinkingof the sodium alginater, freeze drying the first aqueous solution toform a second layer comprising a hydrogel having ORC particles embeddedtherein, dissolving a sodium alginater in water to form a second aqueoussolution, pouring the second aqueous solution into the mold, spraying orinfusing calcium chloride to contact the second aqueous solution toinitiate crosslinking of the sodium alginater, freeze drying the secondaqueous solution to form a third layer comprising a hydrogel.

In various embodiments, a method of manufacturing a tissue thicknesscompensator comprising at least one medicament stored and/or absorbedtherein may generally comprise providing a tissue thickness compensatorand contacting the tissue thickness compensator and the medicament toretain the medicament in the tissue thickness compensator. In at leastone embodiment, a method of manufacturing a tissue thickness compensatorcomprising an antibacterial material may comprise providing a hydrogel,drying the hydrogel, swelling the hydrogel in an aqueous solution ofsilver nitrate, contacting the hydrogel and a solution of sodiumchloride to form the tissue thickness compensator having antibacterialproperties. The tissue thickness compensator may comprise silverdispersed therein.

Referring to FIG. 204, in various embodiments, a method formanufacturing a tissue thickness compensator may comprise co-extrusionand/or bonding. In various embodiments, the tissue thickness compensator70550 may comprise a laminate comprising a first layer 70555 and asecond layer 70560 sealingly enclosing an inner layer 70565 comprising ahydrogel, for example. The hydrogel may comprise a dry film, a dry foam,a powder, and/or granules, for example. The hydrogel may comprise superabsorbent materials, such as, for example, polyvinylpyrrolidone, carboxymethylcellulose, poly sulful propyl acrylate. The first and/or secondlayers may be made in-line by feeding raw materials of the first andsecond layers, respectively, into an extruder from a hopper, andthereafter supplying the first and second layers. The raw materials ofthe inner layer 70565 may be added to a hopper of an extruder. The rawmaterials can be dispersively mixed and compounded at an elevatedtemperature within the extruder. As the raw materials exit the die 70570at an opening, the inner layer 70565 may be deposited onto a surface ofthe first layer 70555. In various embodiments, the tissue thicknesscompensator may comprise a foam, film, powder, and/or granule. The firstand second layers 70555 and 70560 may be positioned in the face-to-facerelationship. The second layer 70560 may be aligned with the first layer70555 in a face-to-face relationship by a roller 70575. The first layer70555 may adhere to the second layer 70560 wherein the first and secondlayers 70555, 70560 may physically entrap the inner layer 70565. Thelayers may be joined together under light pressure, under conventionalcalendar bonding processes, and/or through the use of adhesives, forexample, to form the tissue thickness compensator 70550. In at least oneembodiment, as shown in FIG. 78, the first and second layers 70555 and70560 may be joined together through a rolling process utilizing agrooved roller 70580, for example. In various embodiments, as a resultof the above, the inner layer 70565 may be contained and/or sealed bythe first and second layers 70555 and 70560 which can collectively forman outer layer, or barrier. The outer layer may prevent or reducemoisture from contacting the inner layer 70565 until the outer layer isruptured.

Referring to FIG. 61, an end effector 12 for a surgical instrument 10(FIG. 1) can be configured to receive a fastener cartridge assembly,such as staple cartridge 20000, for example. As illustrated in FIG. 61,the staple cartridge 20000 can be configured to fit in a cartridgechannel 20072 of a jaw 20070 of the end effector 12. In otherembodiments, the staple cartridge 20000 can be integral to the endeffector 12 such that the staple cartridge 20000 and the end effector 12are formed as a single unit construction. The staple cartridge 20000 cancomprise a first body portion, such as rigid support portion 20010, forexample. The staple cartridge 20000 can also comprise a second bodyportion, such as a compressible portion or a tissue thicknesscompensator 20020, for example. In other embodiments, the tissuethickness compensator 20020 may not comprise an integral part of thestaple cartridge 20000 but may be otherwise positioned relative to theend effector 12. For example, the tissue thickness compensator 20020 canbe secured to an anvil 20060 of the end effector 12 or can be otherwiseretained in the end effector 12. In at least one embodiment, referringto FIG. 78, the staple cartridge can further comprise retainer clips20126 which can be configured to inhibit the tissue thicknesscompensator 20020 from prematurely detaching from the support portion20010. The reader will appreciate that the tissue thickness compensatorsdescribed herein can be installed in or otherwise engaged with a varietyof end effectors and that such embodiments are within the scope of thepresent disclosure.

Similar to the tissue thickness compensators described herein, referringnow to FIG. 78, the tissue thickness compensator 20020 can be releasedfrom or disengaged with the surgical end effector 12. For example, insome embodiments, the rigid support portion 20010 of the staplecartridge 20000 can remain engaged with the fastener cartridge channel20072 of the end effector jaw 20070 while the tissue thicknesscompensator 20020 disengages from the rigid support portion 20010. Invarious embodiments, the tissue thickness compensator 20020 can releasefrom the end effector 12 after staples 20030 (FIGS. 78-83) are deployedfrom staple cavities 20012 in the rigid support portion 2010, similar tovarious embodiments described herein. Staples 20030 can be fired fromstaple cavities 20012 such that the staples 20030 engage the tissuethickness compensator 20020. Also similar to various embodimentsdescribed herein, referring generally to FIGS. 63, 82 and 83, a staple20030 can capture a portion of the tissue thickness compensator 20020along with stapled tissue T. In some embodiments, the tissue thicknesscompensator 20020 can be deformable and the portion of the tissuethickness compensator 20020 that is captured within a fired staple 20030can be compressed. Similar to the tissue thickness compensatorsdescribed herein, the tissue thickness compensator 20020 can compensatefor different thicknesses, compressibilities, and/or densities of tissueT captured within each staple 20030. Further, as also described herein,the tissue thickness compensator 20020 can compensate for gaps createdby malformed staples 20030.

The tissue thickness compensator 20020 can be compressible betweennon-compressed height(s) and compressed height(s). Referring to FIG. 78,the tissue thickness compensator 20020 can have a top surface 20021 anda bottom surface 20022. The height of the tissue thickness compensatorcan be the distance between the top surface 20021 and the bottom surface20022. In various embodiments, the non-compressed height of the tissuethickness compensator 20020 can be the distance between the top surface20021 and the bottom surface 20022 when minimal or no force is appliedto the tissue thickness compensator 20020, i.e., when the tissuethickness compensator 20020 is not compressed. The compressed height ofthe tissue thickness compensator 20020 can be the distance between thetop surface 20021 and the bottom surface 20022 when a force is appliedto the tissue thickness compensator 20020, such as when a fired staple20030 captures a portion of the tissue thickness compensator 20020, forexample. The tissue thickness compensator 20020 can have a distal end20025 and a proximal end 20026. As illustrated in FIG. 78, thenon-compressed height of the tissue thickness compensator 20020 can beuniform between the distal end 20025 and the proximal end 20026 of thetissue thickness compensator 20020. In other embodiments, thenon-compressed height can vary between the distal end 20025 and theproximal end 20026. For example, the top surface 20021 and/or bottomsurface 20022 of the tissue thickness compensator 20020 can be angledand/or stepped relative to the other such that the non-compressed heightvaries between the proximal end 20026 and the distal end 20025. In someembodiments, the non-compressed height of the tissue thicknesscompensator 20020 can be approximately 0.08 inches, for example. Inother embodiments, the non-compressed height of the tissue thicknesscompensator 20020 can vary between approximately 0.025 inches andapproximately 0.10 inches, for example.

As described in greater detail herein, the tissue thickness compensator20020 can be compressed to different compressed heights between theproximal end 20026 and the distal end 20025 thereof. In otherembodiments, the tissue thickness compensator 20020 can be uniformlycompressed throughout the length thereof. The compressed height(s) ofthe tissue thickness compensator 20020 can depend on the geometry of theend effector 12, characteristics of the tissue thickness compensator20020, the engaged tissue T and/or the staples 20030, for example. Invarious embodiments, the compressed height of the tissue thicknesscompensator 20020 can relate to the tissue gap in the end effector 12.In various embodiments, when the anvil 20060 is clamped towards thestaple cartridge 20000, the tissue gap can be defined between a top decksurface 20011 (FIG. 78) of the staple cartridge 20000 and a tissuecontacting surface 20061 (FIG. 61) of the anvil 20060, for example. Thetissue gap can be approximately 0.025 inches or approximately 0.100inches, for example. In some embodiments, the tissue gap can beapproximately 0.750 millimeters or approximately 3.500 millimeters, forexample. In various embodiments, the compressed height of the tissuethickness compensator 20020 can equal or substantially equal the tissuegap, for example. When tissue T is positioned within the tissue gap ofthe end effector 12, the compressed height of the tissue thicknesscompensator can be less in order to accommodate the tissue T. Forexample, where the tissue gap is approximately 0.750 millimeters, thecompressed height of the tissue thickness compensator can beapproximately 0.500 millimeters. In embodiments where the tissue gap isapproximately 3.500 millimeters, the compressed height of the tissuethickness compensator 20020 can be approximately 2.5 mm, for example.Furthermore, the tissue thickness compensator 20020 can comprise aminimum compressed height. For example, the minimum compressed height ofthe tissue thickness compensator 20020 can be approximately 0.250millimeters. In various embodiments, the tissue gap defined between thedeck surface of the staple cartridge and the tissue contacting surfaceof the anvil can equal, or at least substantially equal, theuncompressed height of the tissue thickness compensator, for example.

Referring primarily to FIG. 62, the tissue thickness compensator 20020can comprise a fibrous, nonwoven material 20080 including fibers 20082.In some embodiments, the tissue thickness compensator 20020 can comprisefelt or a felt-like material. Fibers 20082 in the nonwoven material20080 can be fastened together by any means known in the art, including,but not limited to, needle-punching, thermal bonding,hydro-entanglement, ultrasonic pattern bonding, chemical bonding, andmeltblown bonding. Further, in various embodiments, layers of nonwovenmaterial 20080 can be mechanically, thermally, or chemically fastenedtogether to form the tissue thickness compensator 20020. As described ingreater detail herein, the fibrous, nonwoven material 20080 can becompressible, which can enable compression of the tissue thicknesscompensator 20020. In various embodiments, the tissue thicknesscompensator 20020 can comprise a non-compressible portion as well. Forexample, the tissue thickness compensator 20020 can comprise acompressible nonwoven material 20080 and a non-compressible portion.

Still referring primarily to FIG. 62, the nonwoven material 20080 cancomprise a plurality of fibers 20082. At least some of the fibers 20082in the nonwoven material 20080 can be crimped fibers 20086. The crimpedfibers 20086 can be, for example, crimped, twisted, coiled, bent,crippled, spiraled, curled, and/or bowed within the nonwoven material20080. As described in greater detail herein, the crimped fibers 20086can be formed in any suitable shape such that deformation of the crimpedfibers 20086 generates a spring load or restoring force. In someembodiments, the crimped fibers 20086 can be heat-shaped to form acoiled or substantially coil-like shape. The crimped fibers 20086 can beformed from non-crimped fibers 20084. For example, non-crimped fibers20084 can be wound around a heated mandrel to form a substantiallycoil-like shape.

In various embodiments, the tissue thickness compensator 20020 cancomprise a homogeneous absorbable polymer matrix. The homogenousabsorbable polymer matrix can comprise a foam, gel, and/or film, forexample. Further, the plurality of fibers 20082 can be dispersedthroughout the homogenous absorbable polymer matrix. At least some ofthe fibers 20082 in the homogenous absorbable polymer matrix can becrimped fibers 20086, for example. As described in greater detailherein, the homogeneous absorbable polymer matrix of the tissuethickness compensator 2002 can be compressible.

In various embodiments, referring to FIGS. 65 and 66, crimped fibers20086 can be randomly dispersed throughout at least a portion of thenonwoven material 20080. For example, crimped fibers 20086 can berandomly dispersed throughout the nonwoven material 20080 such that aportion of the nonwoven material 20080 comprises more crimped fibers20086 than other portions of the nonwoven material 20080. Further, thecrimped fibers 20086 can congregate in fiber clusters 20085 a, 20085 b,20085 c, 20085 d and 20085 e, for example, in the nonwoven material20080. The shape of the crimped fibers 20086 can cause entanglement ofthe fibers 20086 during manufacturing of the nonwoven material 20080;entanglement of the crimped fibers 20086 can, in turn, result in theformation of the fiber clusters 20085 a, 20085 b, 20085 c, 20085 d and20085 e. Additionally or alternatively, crimped fibers 20086 can berandomly oriented throughout the nonwoven material 20080. For example,referring to FIG. 62, a first crimped fiber 20086 a can be oriented in afirst direction, a second crimped fiber 20086 b can be oriented in asecond direction, and a third crimped fiber 20086 c can be oriented in athird direction.

In some embodiments, the crimped fibers 20086 can be systematicallydistributed and/or arranged throughout at least a portion of thenonwoven material 20080. For example, referring now to FIG. 67, crimpedfibers 20186 can be positioned in an arrangement 20185, in which aplurality of crimped fibers 20186 a are arranged in a first directionand another plurality of crimped fibers 20186 b are arranged in a seconddirection. The crimped fibers 20186 can overlap such that they becomeentangled or interconnected with each other. In various embodiments, thecrimped fibers 20186 can be systematically arranged such that a crimpedfiber 20186 a is substantially parallel to another crimped fiber 20186a. Still another crimped fiber 20186 b can be substantially transverseto some crimped fibers 20186 a. In various embodiments, crimped fibers20186 a can be substantially aligned with a first axis Y and crimpedfibers 20186 b can be substantially aligned with a second axis X. Insome embodiments the first axis Y can be perpendicular or substantiallyperpendicular to the second axis X, for example.

Referring primarily to FIG. 68, in various embodiments, crimped fibers20286 can be arranged in an arrangement 20285. In some embodiments, eachcrimped fibers 20286 can comprise a longitudinal axis defined between afirst end 20287 and a second end 20289 of the crimped fiber 20286. Insome embodiments, the crimped fibers 20286 can be systematicallydistributed in the nonwoven material 20080 such that a first end 20287of one crimped fiber 20286 is positioned adjacent to a second end 20289of another crimped fiber 20286. In another embodiment, referring now toFIG. 69, a fiber arrangement 20385 can comprise a first crimped fiber20386 a oriented in a first direction, a second crimped fiber 20386 boriented in a second direction, and a third crimped fiber 20386 coriented in a third direction, for example. In various embodiments, asingle pattern or arrangement of crimped fibers 20286 can be repeatedthroughout the nonwoven material 20080. In at least one embodiment,crimped fibers can be arranged in different patterns throughout thenonwoven material 20080. In still other embodiments, the nonwovenmaterial 20080 can comprise at least one pattern of crimped fibers, aswell as a plurality of randomly oriented and/or randomly distributedcrimped fibers.

Referring again to FIG. 62, the plurality of fibers 20082 in thenonwoven material 20080 can comprise at least some non-crimped fibers20084. The non-crimped fibers 20084 and crimped fibers 20086 in thenonwoven material 20080 can be entangled or interconnected. In oneembodiment, the ratio of crimped fibers 20086 to non-crimped fibers20084 can be approximately 25:1, for example. In another embodiment, theratio of crimped fibers 20086 to non-crimped fibers 20084 can beapproximately 1:25, for example. In other embodiments, the ratio ofcrimped fibers 20086 to non-crimped fibers 20084 can be approximately1:1, for example. As described in greater detail herein, the number ofcrimped fibers 20086 per unit volume of nonwoven material 20080 canaffect the restoring force generated by the nonwoven material 20080 whenthe nonwoven material 20080 has been deformed. As also described ingreater detail herein, the restoring force generated by the nonwovenmaterial 20080 can also depend on, for example, the material, shape,size, position and/or orientation of crimped and non-crimped fibers20086, 20084 in the nonwoven material 20080.

In various embodiments, the fibers 20082 of the nonwoven material 20080can comprise a polymeric composition. The polymeric composition of thefibers 20082 can comprise non-absorbable polymers, absorbable polymers,or combinations thereof. In some embodiments, the absorbable polymerscan include bioabsorbable, biocompatible elastomeric polymers.Furthermore, the polymeric composition of the fibers 20082 can comprisesynthetic polymers, non-synthetic polymers, or combinations thereof.Examples of synthetic polymers include, but are not limited to,polyglycolic acid (PGA), poly(lactic acid) (PLA), polycaprolactone(PCL), polydioxanone (PDO), and copolymers thereof. For example, thefibers 20082 can comprise a 90/10 poly(glycolide-L-lactide) copolymer,such as, for example, the copolymer commercially available from Ethicon,Inc. under the trade designation “VICRYL (polyglactic 910).” Examples ofnon-synthetic polymers include, but are not limited to, lyophilizedpolysaccharide, glycoprotein, elastin, proteoglycan, gelatin, collagen,and oxidized regenerated cellulose (ORC). In various embodiments,similar to the polymeric compositions in tissue thickness compensatorsdescribed herein, the polymeric composition of the fibers 20082 caninclude varied amounts of absorbable polymers, non-absorbable polymers,synthetic polymers, and/or non-synthetic polymers, for example, byweight percentage.

In some embodiments, the crimped fibers 20086 of the nonwoven material20080 can comprise a first polymeric composition and the non-crimpedfibers 20084 of the nonwoven material 20080 can comprise a differentpolymeric composition. For example, the crimped fibers 20086 cancomprise synthetic polymer(s), such as, for example, 90/10poly(glycolide-L-lactide), while the non-crimped fibers 20084 cancomprise non-synthetic polymer(s), such as, for example, oxidizedregenerated cellulose. In other embodiments, the crimped fibers 20086and the non-crimped fibers 20084 can comprise the same polymericcomposition.

As described herein, crimped fibers 20086 and non-crimped fibers 20084can be fastened together, for example, by needle-punching, thermalbonding, hydro-entanglement, ultrasonic pattern bonding, chemicalbonding, and meltblown bonding. In some embodiments, crimped fibers20086 comprising synthetic polymers such as, for example, “VICRYL(polyglactic 910)”, and non-crimped fibers 20084 comprising oxidizedregenerated cellulose can be needle-punched together to form thenonwoven material 20080. In various embodiments, the nonwoven material20080 can comprise approximately 5% to 50% crimped “VICRYL (polyglactic910)” fibers 20086 by weight and approximately 5% to 50% non-crimpedoxidized regenerated cellulose (ORC) fibers 20084 by weight, forexample. When the nonwoven material 20080 contacts tissue T, thenon-crimped ORC fibers 20084 can rapidly react with plasma in the tissueto form a gelatinous mass, for example. In various embodiments, theformation of the gelatinous ORC mass can be instantaneous or nearlyinstantaneous with the tissue contact. Further, after the formation ofthe gelatinous ORC mass, the crimped “VICRYL (polyglactic 910)” fibers20086 can remain dispersed throughout the nonwoven material 20080. Forexample, the crimped fibers 20086 can be suspended in the gelatinous ORCmass. As the gelatinous ORC mass is bioabsorbed, the crimped “VICRYL(polyglactic 910)” fibers 20086 can exert a springback force on adjacenttissue, as described in greater detail herein. Further, the tissue canbegin to heal around the “VICRYL (polyglactic 910)” fibers and/or theformed staples 30030, as also described in greater detail herein.

In at least one embodiment, referring primarily to FIGS. 78-81, thesupport portion 20010 of the staple cartridge 20000 can comprise acartridge body 20017, a top deck surface 20011, and a plurality ofstaple cavities 20012. Similar to the embodiments described herein, eachstaple cavity 20012 can define an opening in the deck surface 20011. Astaple 20030 can be removably positioned in a staple cavity 20012. Invarious embodiments, a single staple 20030 is disposed in each staplecavity 20012. In at least one embodiment, referring primarily to FIGS.82 and 83 and similar to the staples described herein, each staple 20030can comprise a base 20031 having a first end 20035 and a second end20036. A staple leg 20032 can extend from the first end 20035 of thebase 20031 and another staple leg 20032 can extend from the second end20036 of the base 20031. Referring again to FIGS. 78-81, prior to thedeployment of the staples 20030, the base 20031 of each staple 20030 canbe supported by a staple driver 20040 positioned within the rigidsupport portion 20010 of the staple cartridge 20000. Also prior todeployment of the staples 20030, the legs 20032 of each staple 20030 canbe at least partially contained within a staple cavity 20012.

In various embodiments, the staples 20030 can be deployed between aninitial position and a fired position. For example, referring primarilyto FIG. 81, staples 20030 can be in an initial position (staples 20030e, 20030 f), a partially fired or intermediate position (staples 20030c, 20030 d), or a fired position (staples 20030 a, 20030 b). A driver20040 can motivate the staples between the initial position and thefired position. For example, the base 20031 of each staple 20030 can besupported by a driver 20040. The legs 20032 of a staple (staples 20030e, 20030 f in FIG. 80, for example) can be positioned within a staplecavity 20012. As the firing member or staple-firing sled 20050translates from the proximal end 20001 to the distal end 20002 of thestaple cartridge 20000, an inclined surface 20051 on the sled 20050 cancontact an inclined surface 20042 on a driver 20040 to deploy the staple20030 positioned above to the contacted driver 20040. In variousembodiments, the staples 20030 can be deployed between an initialposition and a fired position such that the legs 20032 move through thenonwoven material 20080 of the tissue thickness compensator 20020,penetrate the top surface 20021 of the tissue thickness compensator20020, penetrate tissue T, and contact an anvil 20060 (FIG. 61)positioned opposite the staple cartridge 20000 in the end effector 12.The staple legs 20032 can be deformed against the anvil 20060 and thelegs 20032 of each staple 20030 can capture a portion of the nonwovenmaterial 20080 and a portion of the tissue T.

In the fired configuration (FIGS. 82 and 83), each staple 20030 canapply a compressive force to the tissue T and to the tissue thicknesscompensator 20020 captured within the staple 20030. Referring primarilyto FIGS. 80 and 81, the legs 20032 of each staple 20030 can be deformeddownwardly toward the base 20031 of the staple 20030 to form a stapleentrapment area 20039. The staple entrapment area 20039 can be the areain which the tissue T and the tissue thickness compensator 20020 can becaptured by a fired staple 20030. In various circumstances, the stapleentrapment area 20039 can be defined between the inner surfaces of thedeformed legs 20032 and the inner surface of the base 20031 of a staple20030. The size of the entrapment area 20039 for a staple 20030 candepend on several factors such as the length of the legs, the diameterof the legs, the width of the base, and/or the extent in which the legsare deformed, for example.

In various embodiments, when a nonwoven material 20080 is captured in astaple entrapment area 20039, the captured portion of the nonwovenmaterial 20080 can be compressed. The compressed height of the nonwovenmaterial 20080 captured in a staple entrapment area 20039 can varywithin the staple cartridge 20000 depending on the tissue T in that samestaple entrapment area 20039. For example, where the tissue T isthinner, the staple entrapment area 20039 may have more room for thenonwoven material 20080 and, as a result, the nonwoven material 20080may not be as compressed as it would be if the tissue T were thicker.Where the tissue T is thicker, the nonwoven material 20080 can becompressed more to accommodate the thicker tissue T, for example. Forexample, referring to FIG. 82, the nonwoven material 20080 can becompressed to a first height in a first staple entrapment area 20039 a,a second height in a second staple entrapment area 20039 b, a thirdheight in a third staple entrapment area 20039 c, a fourth height in afourth staple entrapment area 20039 d, and a fifth height in a fifthstaple entrapment area 20039 e, for example. Similarly, as illustratedin FIG. 83, the nonwoven material 20080 can be compressed to a firstheight in the first staple entrapment area 20039 a, a second height inthe second staple entrapment area 20039 b, a third height in the thirdstaple entrapment area 20039 c, and a fourth height in the fourth stapleentrapment area 20039 d. In other embodiments, the compressed height ofthe nonwoven material 20080 can be uniform throughout the staplecartridge 20010.

In various embodiments, an applied force can move the nonwoven material20080 from an initial uncompressed configuration to a compressedconfiguration. Further, the nonwoven material 20080 can be resilient,such that, when compressed, the nonwoven material 20080 can generate aspringback or restoring force. When deformed, the nonwoven material20080 can seek to rebound from the compressed or deformed configuration.As the nonwoven material 20080 seeks to rebound, it can exert aspringback or restoring force on the tissue also captured in the stapleentrapment area 30039, as described in greater detail herein. When theapplied force is subsequently removed, the restoring force can cause thenonwoven material to rebound from the compressed configuration. Invarious embodiments, the nonwoven material 20080 can rebound to theinitial, uncompressed configuration or may rebound to a configurationsubstantially similar to the initial, uncompressed configuration. Invarious embodiments, the deformation of the nonwoven material 20080 canbe elastic. In some embodiments, the deformation of the nonwovenmaterial can be partially elastic and partially plastic.

When a portion of the nonwoven material 20080 is compressed in a stapleentrapment area 20039, the crimped fibers 20086 in that portion of thenonwoven compensator 20039 can also be compressed or otherwise deformed.The amount a crimped fiber 20086 is deformed can correspond to theamount that the captured portion of the nonwoven material 20080 iscompressed. For example, referring to FIG. 63, the nonwoven material20080 can be captured by deployed staples 20030. Where the nonwovenmaterial 20080 is more compressed by a deployed staple 20030, theaverage deformation of crimped fibers 20086 can be greater. Further,where the nonwoven material 20080 is less compressed by a deployedstaple, the average deformation of crimped fibers 20086 can be smaller.Similarly, referring to FIGS. 82 and 83, in a staple entrapment area20039 d where the nonwoven material 20080 is more compressed, thecrimped fibers 20086 in that staple entrapment area 20039 d can be, onaverage, more deformed. Further, in a staple entrapment area 20039 awhere the nonwoven material 20080 is less compressed, the crimped fibers20086 in that staple entrapment area 20039 a can be, on average, lessdeformed.

The ability of the nonwoven material 20080 to rebound from the deformedconfiguration, i.e., the resiliency of the nonwoven material 20080, canbe a function of the resiliency of the crimped fibers 20086 in thenonwoven material 20080. In various embodiments, the crimped fibers20086 can deform elastically. In some embodiments, deformation of thecrimped fibers 20086 can be partially elastic and partially plastic. Invarious embodiments, compression of each crimped fiber 20086 can causethe compressed crimped fibers 20086 to generate a springback orrestoring force. For example, the compressed crimped fibers 20086 cangenerate a restoring force as the fibers 20086 seek to rebound fromtheir compressed configuration. In various embodiments, the fibers 20086can seek to return to their initial, uncompressed configuration or to aconfiguration substantially similar thereto. In some embodiments, thecrimped fibers 20086 can seek to partially return to their initialconfiguration. In various embodiments, only a portion of the crimpedfibers 20086 in the nonwoven material 20080 can be resilient. When acrimped fiber 20086 is comprised of a linear-elastic material, therestoring force of the compressed crimped fiber 20086 can be a functionof the amount the crimped fiber 20086 is compressed and the spring rateof the crimped fiber 20086, for example. The spring rate of the crimpedfiber 20086 can at least depend on the orientation, material, shapeand/or size of the crimped fiber 20086, for example.

In various embodiments, the crimped fibers 20086 in the nonwovenmaterial 20080 can comprise a uniform spring rate. In other embodiments,the spring rate of the crimped fibers 20086 in the nonwoven material20080 can vary. When a crimped fiber 20086 having a large spring rate isgreatly compressed, the crimped fiber 20086 can generate a largerestoring force. When a crimped fiber 20086 having the same large springrate is less compressed, the crimped fiber 20086 can generate a smallerrestoring force. The aggregate of restoring forces generated bycompressed crimped fibers 20086 in the nonwoven material 20080 cangenerate a combined restoring force throughout the nonwoven material20080 of the tissue thickness compensator 20020. In various embodiments,the nonwoven material 20080 can exert the combined restoring force ontissue T captured within a fired staple 20030 with the compressednonwoven material 20080.

Furthermore, the number of crimped fibers 20086 per unit volume ofnonwoven material 20080 can affect the spring rate of the nonwovenmaterial 20080. For example, the resiliency in a nonwoven material 20080can be low when the number of crimped fibers 20086 per unit volume ofnonwoven material 20080 is low, for example; the resiliency of thenonwoven material 20080 can be higher when the number of crimped fibers20086 per unit volume of nonwoven material 20080 is higher, for example;and the resiliency of the nonwoven material 20080 can be higher stillwhen the number of crimped fibers 20086 per unit volume of nonwovenmaterial 20080 is even higher, for example. When the resiliency of thenonwoven material 20080 is low, such as when the number of crimpedfibers 20086 per unit volume of nonwoven material 20080 is low, thecombined restoring force exerted by the tissue thickness compensator20020 on captured tissue T can also be low. When the resiliency of thenonwoven material 20080 is higher, such as when the number of crimpedfibers 20086 per unit volume of nonwoven material 20080 is higher, theaggregate restoring force exerted by the tissue thickness compensator20020 on captured tissue T can also be higher.

In various embodiments, referring primarily to FIG. 64, a nonwovenmaterial 20080′ of a tissue thickness compensator 20020′ can comprise atherapeutic agent 20088, such as a medicament and/or pharmaceuticallyactive agent, for example. In various embodiments, the nonwoven material20080′ can release a therapeutically effective amount of the therapeuticagent 20088. For example, the therapeutic agent 20088 can be released asthe nonwoven material 20080′ is absorbed. In various embodiments, thetherapeutic agent 20088 can be released into fluid, such as blood, forexample, passing over or through the nonwoven material 20080′. Examplesof therapeutic agents 20088 can include, but are not limited to,haemostatic agents and drugs such as, for example, fibrin, thrombin,and/or oxidized regenerated cellulose (ORC); anti-inflammatory drugssuch as, for example, diclofenac, aspirin, naproxen, sulindac, and/orhydrocortisone; antibiotic and antimicrobial drugs or agents such as,for example, triclosan, ionic silver, ampicillin, gentamicin, polymyxinB, and/or chloramphenicol; and anticancer agents such as, for example,cisplatin, mitomycin, and/or adriamycin. In various embodiments, thetherapeutic agent 20088 can comprise a biologic, such as a stem cell,for example. In some embodiments, the fibers 20082 of the nonwovenmaterial 20080′ can comprise the therapeutic agent 20088. In otherembodiments, the therapeutic agent 20088 can be added to the nonwovenmaterial 20080′ or otherwise integrated into the tissue thicknesscompensator 20020′.

In some embodiments, primarily referring to FIGS. 70-70B, a tissuethickness compensator 20520 for an end effector 12 (FIG. 61) cancomprise a plurality of springs or coiled fibers 20586. Similar to thecrimped fibers 20086 described herein, the coiled fibers 20586 can be,for example, crimped, twisted, coiled, bent, crippled, spiraled, curled,and/or bowed within the tissue thickness compensator 20520. In someembodiments, the coiled fibers 20586 can be wound around a mandrel toform a coiled or substantially coil-like shape. Similar to theembodiments described herein, the coiled fibers 20586 can be randomlyoriented and/or randomly distributed throughout the tissue thicknesscompensator 20520. In other embodiments, the coiled fibers 20586 can besystematically arranged and/or uniformly distributed throughout thetissue thickness compensator 20520. For example, referring to FIG. 70,the coiled fibers 20586 can comprise a longitudinal axis between a firstend 20587 and a second end 20589 of the coiled fiber 20586. Thelongitudinal axes of the coiled fibers 20520 in the tissue thicknesscompensator 20520 can be parallel or substantially parallel. In someembodiments, the first end 20587 of each coiled fiber 20520 can bepositioned along a first longitudinal side 20523 of the tissue thicknesscompensator 20520 and the second end 20589 of each coiled fiber 20586can be positioned along a second longitudinal side 20524 of the tissuethickness compensator 20520. In such an arrangement, the coiled fibers20586 can laterally traverse the tissue thickness compensator. In otherembodiments, the coiled fibers 20586 can longitudinally or diagonallytraverse the tissue thickness compensator 20520.

In various embodiments, similar to the crimped fibers 20086 describedherein, the coiled fibers 20586 can comprise a polymeric composition.The crimped fibers 20586 can be at least partially elastic such thatdeformation of the crimped fibers 20586 generates a restoring force. Insome embodiments, the polymeric composition of the coiled fibers 20586can comprise polycaprolactone (PCL), for example, such that the coiledfibers 20586 are not soluble in a chlorophyll solvent. Referring to FIG.70A, the springs or coiled fibers 20520 can be retained in acompensation material 20580. In various embodiments, the compensationmaterial 20580 can hold the coiled fibers 20586 in a loaded positionsuch that the coiled fibers 20586 exert a spring load on, or within, thecompensation material 20580. In certain embodiments, the compensationmaterial 20580 can hold the coiled fibers 20586 in a neutral positionwhere the coiled fibers 20586 are not exerting a spring load on, orwithin, the compensation material 20580. The compensation material 20580can be bioabsorbable and, in some embodiments, can comprise a foam, suchas, for example, polyglycolic acid (PGA) foam. Furthermore, thecompensation material 20580 can be soluble in a chlorophyll solvent, forexample. In some embodiments the tissue thickness compensator cancomprise coiled fibers 20586 that comprise polycaprolactone (PCL) andcompensation material 20580 that comprises polyglycolic acid (PGA) foam,for example, such that the coiled fibers 20520 are not soluble in achlorophyll solvent while the compensation material 20580 is soluble inthe chlorophyll solvent. In various embodiments, the compensationmaterial 20580 can be at least partially elastic, such that compressionof the compensation material 20580 generates a restoring force. Further,similar to the embodiments described herein, referring to FIG. 70B, thecompensation material 20580 of the tissue thickness compensator 20520can comprise a therapeutic agent 20588, such as stem cells, for example.The compensation material 20580 can release a therapeutically effectiveamount of the therapeutic agent 20588 as the compensation material 20580is absorbed.

Similar to the tissue thickness compensator 20020 described herein, thetissue thickness compensator 20520 can be compressible. For example, asstaples 20030 (FIGS. 78-81) are deployed from an initial position to afired position, the staples 20030 can engage a portion of tissuethickness compensator 20520. In various embodiments, a staple 20030 cancapture a portion of the tissue thickness compensator 20520 and adjacenttissue T. The staple 20030 can apply a compressive force to the capturedportion of the tissue thickness compensator 20520 and tissue T such thatthe tissue thickness compensator 20520 is compressed from anon-compressed height to a compressed height. Similar to the embodimentsdescribed herein, compression of the tissue thickness compensator 20520can result in a corresponding deformation of the coiled fibers 20586therein. As described in greater detail herein, deformation of eachcoiled fiber 20586 can generate a restoring force that can depend on theresiliency of the coiled fiber, for example, the amount the coiled fiber20586 is deformed and/or the spring rate of the coiled fiber 20586. Thespring rate of the coiled fiber 20586 can at least depend on theorientation, material, shape and/or size of the coiled fiber 20586, forexample. Deformation of the coiled fibers 20586 in the tissue thicknesscompensator 20520 can generate restoring forces throughout the tissuethickness compensator 20520. Similar to the embodiments describedherein, the tissue thickness compensator 20520 can exert the aggregaterestoring force generated by the deformed coiled fibers 20586 and/or theresilient compensation material 20586 on the captured tissue T in thefired staples 20030.

In some embodiments, primarily referring to FIGS. 71 and 72, a tissuethickness compensator 20620 for an end effector 12 can comprise aplurality of spring coils 20686. Similar to the crimped fibers 20086 andcoiled fibers 20586 described herein, spring coils 20686 can be, forexample, crimped, twisted, coiled, bent, crippled, spiraled, curled,and/or bowed within the tissue thickness compensator 20620. In variousembodiments, similar to the fibers and coils described herein, thespring coils 20686 can comprise a polymeric composition. Further, thespring coils 20686 can be at least partially elastic such thatdeformation of the spring coils 20686 generates a restoring force. Thespring coils 20686 can comprise a first end 20687, a second end 20689,and a longitudinal axis therebetween. Referring to FIG. 71, the firstend 20686 of a spring coil 20686 can be positioned at or near a proximalend 20626 of the tissue thickness compensator and the second end 20689of the same spring coil 20686 can be positioned at or near a distal end20625 of the tissue thickness compensator 20620 such that the springcoil 20686 longitudinally traverses the tissue thickness compensator20620, for example. In other embodiments, the coiled fibers 20686 canlaterally or diagonally traverse the tissue thickness compensator 20620.

The tissue thickness compensator 20620 can comprise an outer film 20680that at least partially surrounds at least one spring coil 20686. Invarious embodiments, referring to FIG. 71, the outer film 20680 canextend around the perimeter of multiple spring coils 20686 in the tissuethickness compensator 20620. In other embodiments, the outer film 20680can completely encapsulate the spring coils 20686 or at least one springcoil 20686 in the tissue thickness compensator 20620. The outer film20680 can retain the spring coils 20686 in the end effector 12. Invarious embodiments, the outer film 20680 can hold the spring coils20686 in a loaded position such that the spring coils 20686 generate aspring load and exert a springback force on the outer film 20680. Inother embodiments, the outer film 20680 can hold the spring coils 20686in a neutral position. The tissue thickness compensator 20620 can alsocomprise a filling material 20624. In some embodiments, the fillingmaterial 20624 can be retained within and/or around the spring coils20686 by the outer film 20680. In some embodiments, the filling material20624 can comprise a therapeutic agent 20688, similar to the therapeuticagents described herein. Further, the filling material 20624 can supportthe spring coils 20686 within the tissue thickness compensator 20620.The filling material 20624 can be compressible and at least partiallyresilient, such that the filling material 20624 contributes to thespringback or restoring force generated by the tissue thicknesscompensator 20620, as described in greater detail herein.

Similar to the tissue thickness compensators described herein, thetissue thickness compensator 20620 can be compressible. As staples 20030(FIGS. 78-81) are deployed from an initial position to a fired position,in various embodiments, the staples 20030 can engage a portion of thetissue thickness compensator 20620. In various embodiments, each staple20030 can capture a portion of the tissue thickness compensator 20620along with adjacent tissue T. The staple 20030 can apply a compressiveforce to the captured portion of the tissue thickness compensator 20620and the captured tissue T such that the tissue thickness compensator20620 is compressed between a non-compressed height and a compressedheight. Similar to the embodiments described herein, compression of thetissue thickness compensator 20620 can result in a correspondingdeformation of the spring coils 20686 retained therein (FIG. 72). Asdescribed in greater detail herein, deformation of each spring coils20686 can generate a restoring force that depends on the resiliency ofthe spring coil 20686, for example, the amount the spring coil 20686 isdeformed and/or the spring rate of the spring coil 20686. The springrate of a spring coil 20686 can at least depend on the material, shapeand/or dimensions of the spring coil 20686, for example. Furthermore,depending on the resiliency of the filling material 20624 and the outerfilm 20680, compression of the filling material 20624 and/or the outerfilm 20680 can also generate restoring forces. The aggregate ofrestoring forces generated at least by the deformed spring coils 20686,the filling material 20624 and/or the outer film 20680 in the tissuethickness compensator 20620 can generate restoring forces throughout thetissue thickness compensator 20620. Similar to the embodiments describedherein, the tissue thickness compensator 20620 can exert the aggregaterestoring force generated by the deformed spring coils 20686 on thecaptured tissue T in a fired staple 20030.

In various embodiments, primarily referring to FIGS. 73-75, a tissuethickness compensator 20720 for an end effector 12 can comprise aplurality of spring coils 20786. Similar to the coiled fibers andsprings described herein, spring coils 20786 can be, for example,crimped, twisted, coiled, bent, crippled, spiraled, curled, and/or bowedwithin the tissue thickness compensator 20720. The spring coils 20786can be at least partially elastic such that deformation of the springcoils 20786 generates a restoring force. Further, the spring coils 20786can comprise a first end 20787, a second end 20789, and a longitudinalaxis therebetween. Referring primarily to FIG. 75, the first end 20787of the spring coil 20786 can be positioned at or near a proximal end20726 of the tissue thickness compensator 20720 and the second end 20789of the spring coil 20786 can be positioned at or near a distal end 20725of the tissue thickness compensator 20720 such that the spring coil20786 longitudinally traverses the tissue thickness compensator 20720.In some embodiments, the spring coil 20786 can longitudinally extend intwo parallel rows in the tissue thickness compensator 20720. The tissuethickness compensator 20720 can be positioned in an end effector 12 suchthat a sled 20050 (FIG. 61) or cutting element 20052 can translate alonga slot 20015 between the parallel rows of spring coils 20786. In otherembodiments, similar to various embodiments described herein, the springcoils 20786 can laterally or diagonally traverse the tissue thicknesscompensator 20720.

Referring again to FIG. 75, the spring coils 20786 can be retained orembedded in a compensation material 20780. The compensation material20780 can be bioabsorbable and, in some embodiments, can comprise foam,such as, for example, polyglycolic acid (PGA) foam. In variousembodiments, the compensation material 20780 can be resilient such thatdeformation of the compensation material 20780 generates a springbackforce. The compensation material 20780 can be soluble in a chlorophyllsolvent, for example. In some embodiments, for example, the tissuethickness compensator can comprise spring coils 20786 that comprisepolycaprolactone (PCL) and compensation material 20780 that comprisespolyglycolic acid (PGA) foam such that the spring coils 20786 are notsoluble in a chlorophyll solvent while the compensation material 20780is soluble in a chlorophyll solvent, for example. The compensationmaterial 20780 can be at least partially resilient such that deformationof the compensation material 20780 generates a spring load or restoringforce.

In various embodiments, the tissue thickness compensator 20720 cancomprise interwoven threads 20790, which can extend between parallelrows of spring coils 20786. For example, referring to FIG. 75, a firstinterwoven thread 20790 can diagonally traverse the two parallel rows ofspring coils 20786 and a second interwoven thread 20790 can alsodiagonally traverse the two parallel rows of spring coils 20786. In someembodiments, the first and second interwoven threads 20790 cancrisscross. In various embodiments, the interwoven threads 20790 cancrisscross multiple times along the length of the tissue thicknesscompensator 20720. The interwoven threads 20790 can hold the springcoils 20786 in a loaded configuration such that the spring coils 20786are held in a substantially flat position in the tissue thicknesscompensator 20720. In some embodiments, the interwoven threads 20790that traverse the tissue thickness compensator 20720 can be directlyattached to the spring coils 20786. In other embodiments, the interwoventhreads 20790 can be coupled to the spring coils 20786 via a support20792 that extends through each spring coil 20786 along the longitudinalaxis thereof.

As described in greater detail herein, in various embodiments, a staplecartridge 20000 can comprise a slot 20015 configured to receive atranslating sled 20050 comprising a cutting element 20052 (FIG. 61). Asthe sled 20050 translates along the slot 20015, the sled 20050 can ejectstaples 20030 from fastener cavities 20012 in the staple cartridge 20000and the cutting element 20052 can simultaneously or nearlysimultaneously sever tissue T. In various embodiments, referring againto FIG. 75, as the cutting element 20052 translates, it can also severthe interwoven threads 20790 that crisscross between the parallel rowsof spring coils 20786 in the tissue thickness compensator 20720. As theinterwoven threads 20790 are severed, each spring coil 20786 can bereleased from its loaded configuration such that each spring coil 20786reverts from the loaded, substantially flat position to an expandedposition in the tissue thickness compensator 20720. In variousembodiments, when a spring coil 20786 is expanded, the compensationmaterial 20780 surrounding the spring coil 20786 can also expand.

In various embodiments, as staples 20030 (FIGS. 78-81) are deployed froman initial position to a fired position, the staples 20030 can engage aportion of the tissue thickness compensator 20720 and the tissuethickness compensator 20720 can expand, or attempt to expand, within thestaples 20030 and can apply a compressive force to the tissue T. Invarious embodiments, at least one staple 20030 can capture a portion ofthe tissue thickness compensator 20720, along with adjacent tissue T.The staple 20030 can apply a compressive force to the captured portionof the tissue thickness compensator 20720 and the captured tissue T,such that the tissue thickness compensator 20720 is compressed between anon-compressed height and a compressed height. Similar to theembodiments described herein, compression of the tissue thicknesscompensator 20720 can result in a corresponding deformation of thespring coils 20786 and compensation material 20780 retained therein. Asdescribed in greater detail herein, deformation of each spring coils20786 can generate a restoring force that can depend on the resiliencyof the spring coil, for example, the amount the spring coil 20786 isdeformed and/or the spring rate of the spring coil 20786. The springrate of a spring coil 20786 can at least depend on the orientation,material, shape and/or size of the spring coil 20786, for example. Theaggregate of restoring forces generated by at least the deformed springcoils 20786 and/or the compensation material 30380 in the tissuethickness compensator 20720 can generate restoring forces throughout thetissue thickness compensator 20720. Similar to the embodiments describedherein, the tissue thickness compensator 20720 can exert the aggregaterestoring force generated by the deformed spring coils 20786 in thetissue thickness compensator 20720 on the captured tissue T and firedstaples 20030.

In various embodiments, primarily referring to FIGS. 76 and 77, a tissuethickness compensator 20820 for a surgical end effector 12 can comprisea spring coil 20886. Similar to the fibers and coils described herein,spring coil 20886 can be, for example, crimped, twisted, coiled, bent,crippled, spiraled, curled, and/or bowed within the tissue thicknesscompensator 20820. The spring coil 20886 can comprise a polymericcomposition and can be at least partially elastic, such that deformationof the spring coil 20886 generates a springback force. Further, thespring coil 20886 can comprise a first end 20887 and a second end 20889.Referring to FIG. 76, the first end 20887 can be positioned at or near aproximal end 20826 of the tissue thickness compensator 20820 and thesecond end 20889 can be positioned at or near a distal end 20825 of thetissue thickness compensator 20820. The spring coil 20886 can wind ormeander from the proximal end 20825 to the distal end 20826 of thetissue thickness compensator 20820.

Referring again to FIG. 76, the spring coil 20886 can be retained orembedded in a compensation material 20880. The compensation material20880 can be bioabsorbable and, in some embodiments, can comprise afoam, such as, for example, polyglycolic acid (PGA) foam. Thecompensation material 20880 can be soluble in a chlorophyll solvent, forexample. In some embodiments, the tissue thickness compensator cancomprise spring coils 20886 comprising polycaprolactone (PCL) andcompensation material 20880 comprising polyglycolic acid (PGA) foam, forexample, such that the spring coil 20886 is not soluble in a chlorophyllsolvent while the compensation material 20880 is soluble in achlorophyll solvent. The compensation material 20880 can be at leastpartially resilient such that deformation of the compensation material20880 generates a spring load or restoring force.

Similar to tissue thickness compensators described herein, for example,the tissue thickness compensator 20820 can be compressible. Compressionof the tissue thickness compensator 20820 can result in a deformation ofat least a portion of the spring coil 20886 retained or embedded in thecompensation material 20880 of the tissue thickness compensator 20820.As described in greater detail herein, deformation of the spring coil20886 can generate restoring forces that can depend on the resiliency ofthe spring coil 20886, the amount the spring coil 20886 is deformed,and/or the spring rate of the spring coil 20886, for example. Theaggregate of restoring forces generated by the deformed spring coil20886 and/or deformed compensation material 20880 can generate restoringforces throughout the tissue thickness compensator 20820. The tissuethickness compensator 20820 can exert the aggregate restoring force onthe captured tissue T in the fired staples 20030.

Referring now to FIG. 84, a surgical end effector 12 can comprise atissue thickness compensator 30020 having at least one tubular element30080. The tissue thickness compensator 30020 can be retained in thesurgical end effector 12. As described in greater detail herein, afastener in the end effector 12 can be deployed such that the fastenermoves to a fired position and deforms at least a portion of the tubularelement 30080 in the tissue thickness compensator 30020. The reader willappreciate that tissue thickness compensators comprising at least onetubular element as described herein can be installed in or otherwiseengaged with a variety of surgical end effectors and that suchembodiments are within the scope of the present disclosure.

In various embodiments, still referring to FIG. 84, the tissue thicknesscompensator 30020 can be positioned relative to the anvil 30060 of theend effector 12. In other embodiments, the tissue thickness compensator30020 can be positioned relative to a fastener cartridge assembly, suchas staple cartridge 30000, of the end effector 12. In variousembodiments, the staple cartridge 30000 can be configured to fit in acartridge channel 30072 of a jaw 30070 of the end effector 12. Forexample, the tissue thickness compensator 30020 can be releasablysecured to the staple cartridge 30000. In at least one embodiment, thetubular element 30080 of the tissue thickness compensator 30020 can bepositioned adjacent to a top deck surface 30011 of a rigid supportportion 30010 of the staple cartridge 30000. In various embodiments, thetubular element 30080 can be secured to the top deck surface 30011 by anadhesive or by a wrap, similar to at least one of the wraps describedherein (e.g., FIG. 16). In various embodiments, the tissue thicknesscompensator 30020 can be integral to an assembly comprises the staplecartridge 30000 such that the staple cartridge 30000 and the tissuethickness compensator 30020 are formed as a single unit construction.For example, the staple cartridge 30000 can comprise a first bodyportion, such as the rigid support portion 30010, and a second bodyportion, such as the tissue thickness compensator 30020, for example.

Referring to FIGS. 84-86, the tubular element 30080 in the tissuethickness compensator 30020 can comprise an elongate portion 30082having at least one lumen 30084 that extends at least partiallytherethrough. Referring primarily to FIG. 86, the elongate portion 30082of the tubular element 30080 can comprise woven or braided strands30090, as described in greater detail herein. In other embodiments, theelongate portion 30082 can comprise a solid structure, such as a polymerextrusion, rather than woven strands 30090. The elongate portion 30082of the tubular element 30080 can comprise a thickness. In variousembodiments, the thickness of the elongate portion 30082 can besubstantially uniform throughout the length and around the diameterthereof; in other embodiments, the thickness can vary. The elongateportion 30082 can be elongated such that the length of the elongateportion 30082 is greater than the diameter of the elongate portion30082, for example. In various embodiments, the elongate portion cancomprise a length of approximately 1.20 inches to approximately 2.60inches and a diameter of approximately 0.10 inches to approximately 0.15inches, for example. In some embodiments, the length of the tubularelement 20080 can be approximately 1.40 inches, for example, and thediameter of the tubular element 20080 can be approximately 0.125 inches,for example. Furthermore, the elongate portion 30082 can define asubstantially circular or elliptical cross-sectional shape, for example.In other embodiments, the cross-sectional shape can comprise a polygonalshape, such as, for example, a triangle, a hexagon and/or an octagon.Referring again to FIG. 84, the tubular element 30080 can comprise afirst distal end 30083 and a second proximal end 30085. In variousembodiments, the cross-sectional shape of the elongate portion 30082 cannarrow at the first and/or second end 30083, 30085 wherein at least oneend 30083, 30085 of the tubular element 30080 can be closed and/orsealed. In other embodiments, a lumen 30084 can continue through thedistal ends 30083, 30085 of the tubular element 30080 such that the ends30083, 30085 are open.

In various embodiments, the tubular element 30080 can comprise a singlecentral lumen 30084 that extends at least partially through the elongateportion 30084. In some embodiments, the lumen 30084 can extend throughthe entire length of the elongate portion 30084. In still otherembodiments, the tubular element 30080 can comprise multiple lumens30084 extending therethrough. Lumens 30084 extending through the tubularelement 30080 can be circular, semi-circular, wedge-shaped, and/orcombinations thereof. In various embodiments, a tubular element 30080can also comprise support webs that can form a modified “T” or “X”shape, for example, within the lumen 30084. In various embodiments, thedimensions, lumen(s), and/or support web(s) within the tubular element30080 can define the cross-sectional shape of the tubular element 30080.The cross-sectional shape of the tubular element 30080 can be consistentthroughout the length thereof or, in other embodiments, thecross-sectional shape of the tubular element 30080 can vary along thelength thereof. As described in greater detail herein, thecross-sectional shape of the tubular element 30080 can affect thecompressibility and resiliency of the tubular element 30080.

In various embodiments, the tubular element 30080 can comprise avertical diameter and a horizontal diameter; the dimensions thereof canbe selected depending on the arrangement of the tubular element 30080 inthe end effector 12, the dimensions of the end effector 12, includingthe tissue gap of the end effector 12, and the expected geometry of thestaple entrapment areas 30039. For example, the vertical diameter of thetubular element 30080 can relate to the expected height of a formedstaple. In such embodiments, the vertical diameter of the tubularelement 30080 can be selected such that the vertical diameter can bereduced approximately 5% to approximately 20% when the tubular element30080 is captured within a formed staple 30030. For example, a tubularelement 30080 having a vertical diameter of approximately 0.100 inchesmay be used for staples having an expected formed height ofapproximately 0.080 inches to approximately 0.095 inches. As a result,the vertical diameter of the tubular element 30080 can be reducedapproximately 5% to approximately 20% when captured within the formedstaple 30030 even when no tissue T is captured therein. When tissue T iscaptured within the formed staple 30030, the compression of the tubularelement 30080 may be even greater. In some embodiments, the verticaldiameter can be uniform throughout the length of the tubular element30080 or, in other embodiments, the vertical diameter can vary along thelength thereof.

In some embodiments, the horizontal diameter of the tubular element30080 can be greater than, equal to, or less than the vertical diameterof the tubular element 30080 when the tubular element 30080 is in anundeformed or rebounded configuration. For example, referring to FIG.85, the horizontal diameter can be approximately three times larger thanthe vertical diameter, for example. In some embodiments the horizontaldiameter can be approximately 0.400 inches and the vertical diameter canbe approximately 0.125 inches, for example. In other embodiments,referring now to FIG. 87, the horizontal diameter of a tubular element31080 can be equal to or substantially equal to the vertical diameter ofthe tubular element 31080 when the tubular element 31080 is in anundeformed or rebounded configuration. In some embodiments thehorizontal diameter can be approximately 0.125 inches and the verticaldiameter can also be approximately 0.125 inches, for example. In variousembodiments, the tubular element 30080 can comprise a vertical diameterof approximately 0.125 inches, a horizontal diameter of approximately0.400 inches, and a length of approximately 1.400 inches. As describedin greater detail herein, when a force A is applied to the tubularelement 30080 and/or 31080, the tubular element can deform such that thecross-sectional geometry, including the horizontal and verticaldiameters, can change.

Referring again to FIGS. 84-86, the tubular element 30080 in the tissuethickness compensator 30020 can be deformable. In various embodiments,the entire tubular element 30080 can be deformable. For example, thetubular element 30080 can be deformable from the proximal end 30083 tothe distal end 30085 of the elongate portion 30082 and around the entirecircumference thereof. In other embodiments, only a portion of thetubular element 30080 can be deformable. For example, in variousembodiments, only an intermediate length of the elongate portion 30082and/or only a portion of the circumference of the tubular element 30080can be deformable.

When a compressive force is applied to a contact point on the elongateportion 30082 of the tubular element 30080, the contact point can shift,which can alter the cross-sectional dimensions of the tubular element30080. For example, referring again to FIG. 85, the tubular element30080 can comprise a top apex 30086 and a bottom apex 30088 on theelongate portion 30082. In the initial, undeformed configuration, thetubular element 30080 can comprise undeformed cross-sectionaldimensions, including an undeformed vertical diameter between the topapex 30086 and the bottom apex 30088. When a compressive force A isapplied to the top apex 30086, the tubular element 30080 can move to adeformed configuration. In the deformed configuration, thecross-sectional dimensions of the tube 30080 can be altered. Forexample, the tube 30086 can comprise a deformed vertical diameterbetween the top apex 30086 and the bottom apex 30088, which can be lessthan the undeformed vertical diameter. In some embodiments, referring toFIG. 87, the horizontal diameter of the deformed tube 30080 can belengthened, for example, when the tubular element 30080 moves from anundeformed configuration to a deformed configuration. The deformedcross-sectional dimensions of the deformed tube 30080 can at leastdepend on the position, angular orientation, and/or magnitude of theapplied force A. As described in greater detail herein, deformation of atubular element 30080 can generate a springback or restoring force thatcan depend on the resiliency of the tubular element 30080.

Referring still to FIG. 85, the tubular element 30080 can generate aspringback or restoring force when compressed. In such embodiments, asdescribed herein, the tubular element 30080 can move from an initialundeformed configuration to a deformed configuration when a force A isapplied to a contact point on the elongate portion 30082 of the tubularelement 30080. When the applied force A is removed, the deformed tube30080 can rebound from the deformed configuration. The deformed tube30080 may rebound to the initial, undeformed configuration or mayrebound to a configuration substantially similar to the initial,undeformed configuration. The ability of the tubular element 30080 torebound from a deformed configuration relates to the resiliency of thetubular element 30080.

Referring again to FIG. 85, a tubular element 30080 can exert aspringback or restoring force. The restoring force can be generated bythe tubular element 30080 when an applied force A is exerted on thetubular element 30080, for example, by a staple 30030 (FIGS. 88 and 89),as described in greater detail herein. An applied force A can alter thecross-sectional dimensions of the tubular element 30080. Furthermore, inlinear-elastic materials, the restoring force of each deformed portionof the tubular element 30080 can be a function of the deformeddimensions of the tubular element 30080 and the spring rate of thatportion of the tubular element 30080. The spring rate of a tubularelement 30080 can at least depend on the orientation, material,cross-sectional geometry and/or dimensions of the tubular element 30080,for example. In various embodiments, the tubular element 30080 in atissue thickness compensator 30020 can comprise a uniform spring rate.In other embodiments, the spring rate can vary along the length and/oraround the diameter of the tubular element 30080. When a portion of atubular element 30080 having a first spring rate is greatly compressed,the tubular element 30080 can generate a large restoring force. When aportion of the tubular element 30080 having the same first spring rateis less compressed, the tubular element 30080 can generate a smallerrestoring force.

Referring again to FIG. 84, the tubular element 30080 in the tissuethickness compensator 30020 can comprise a polymeric composition. Insome embodiments, the elongate portion 30082 of the tubular element30080 can comprise the polymeric composition. Further, in variousembodiments, the polymeric composition can comprise an at leastpartially elastic material such that deformation of the tubular element30080 generates a restoring force. The polymeric composition cancomprise non-absorbable polymers, absorbable polymers, or combinationsthereof, for example. Examples of synthetic polymers include, but arenot limited to, polyglycolic acid (PGA), poly(lactic acid) (PLA),polycaprolactone (PCL), polydioxanone (PDO), and copolymers thereof. Insome embodiments, the absorbable polymers can include bioabsorbable,biocompatible elastomeric polymers, for example. Furthermore, thepolymeric composition of the tubular element 30080 can comprisesynthetic polymers, non-synthetic polymers, or combinations thereof, forexample. In various embodiments, similar to the polymeric compositionsin embodiments described herein, the polymeric composition of thetubular element 30080 can include varied amounts of absorbable polymers,non-absorbable polymers, synthetic polymers, and/or non-syntheticpolymers, for example, by weight percentage.

Referring to FIGS. 84 and 85, the tubular element 30080 can comprise atherapeutic agent 30098 such as a pharmaceutically active agent ormedicament, for example. In various embodiments, the therapeutic agent30098 can be retained in the lumen 30084 of the tubular element 30080.The elongate portion 30082 can encapsulate or partially encapsulate thetherapeutic agent 30098. Additionally or alternatively, the polymericcomposition of the elongate portion 30082 can comprise the therapeuticagent 30098. The tubular element 30080 can release a therapeuticallyeffective amount of the therapeutic agent 30098. In various embodiments,the therapeutic agent 30098 can be released as the tubular element 30080is absorbed. For example, the therapeutic agent 30098 can be releasedinto fluid (such as blood) passing over or through the tubular element30080. In still other embodiments, the therapeutic agent 30098 can bereleased when a staple 30030 (FIGS. 88 and 89) pierces the tubularelement 30080 and/or when the cutting element 30052 on the staple-firingsled 30050 (FIG. 84) cuts a portion of the tubular element 30080, forexample. Examples of therapeutic agents 30098 can include, but are notlimited to, haemostatic agents and drugs such as, for example, fibrin,thrombin, and/or oxidized regenerated cellulose (ORC), anti-inflammatorydrugs such as, for example, diclofenac, aspirin, naproxen, sulindac,and/or hydrocortisone, antibiotic and antimicrobial drugs or agents suchas, for example, triclosan, ionic silver, ampicillin, gentamicin,polymyxin B, and/or chloramphenicol, anticancer agents such as, forexample, cisplatin, mitomycin, and/or adriamycin, and/or biologics suchas, for example, stem cells.

In various embodiments, referring again to FIGS. 84, 88 and 89,fasteners such as staples 30030, for example, can be deployed from astaple cartridge 30000 such that the staples 30030 engage a tissuethickness compensator 30020 and apply a force A to a tubular element32080 therein. As described herein, application of a force A to thetubular element 30080 can cause deformation of the tubular element30080. Similar to the end effectors 12 described herein, the rigidsupport portion 30010 of the staple cartridge 30000 can comprise acartridge body 30017, a deck surface 30011, and a plurality of staplecavities 30012 therein. Each staple cavity 30012 can define an openingin the deck surface 30011 and a staple 30030 can be removably positionedin a staple cavity 30012 (FIG. 104). In at least one embodiment,referring primarily to FIGS. 88 and 89, each staple 30030 can comprise abase 30031 and two staple legs 30032 extending from the base 30031.Prior to the deployment of the staples 30030, the base 30031 of eachstaple 30030 can be supported by a staple driver 30040 (FIG. 104)positioned within the rigid support portion 30010 of the staplecartridge 30000. Also prior to the deployment of the staples 30030, thelegs 30032 of each staple 30030 can be at least partially containedwithin the staple cavity 30012 (FIG. 104).

In various embodiments, as described in greater detail herein, thestaples 30030 can be deployed between an initial position and a firedposition. For example, a staple-firing sled 30050 can engage a driver30040 (FIG. 104). to move at least one staple 30030 between the initialposition and the fired position. In various embodiments, referringprimarily to FIG. 88, the staple 30030 can be moved to a fired position,wherein the legs 30032 of the staple 30030 engage a tubular element32080 of a tissue thickness compensator 32020, penetrate tissue T, andcontact an anvil 30060 (FIG. 104) positioned opposite the staplecartridge 30000 in the surgical end effector 12. Staple forming pockets30062 in the anvil 30060 can bend the staple legs 30032 such that thefired staple 30030 captures a portion of the tubular element 32080 and aportion of the tissue T in a staple entrapment area 30039. As describedin greater detail herein, at least one staple leg 30032 can pierce thetubular element 32080 of the tissue thickness compensator 32020 when thestaple 30030 moves between the initial position and the fired position.In other embodiments, the staple legs 30032 can move around theperimeter of the tubular element 32080 such that the staple legs 30032avoid piercing the tubular element 32080. Similar to the fastenersdescribed herein, the legs 30032 of each staple 30030 can be deformeddownwardly toward the base 30031 of the staple 30030 to form a stapleentrapment area 30039 therebetween. The staple entrapment area 30039 canbe the area in which tissue T and a portion of the tissue thicknesscompensator 32020 can be captured by a fired staple 30030. In the firedposition, each staple 30030 can apply a compressive force to the tissueT and to the tissue thickness compensator 32020 captured within thestaple entrapment area 30039 of the staple 30030.

In various embodiments, referring still to FIG. 88, when the tubularelement 32080 is captured in a staple entrapment area 30039, thecaptured portion of the tubular element 32080 can be deformed, asdescribed herein. Furthermore, the tubular element 32080 can be deformedto different deformed configurations in different staple entrapmentareas 30039 depending on, for example, the thickness, compressibility,and/or density of the tissue T captured in that same staple entrapmentarea 30039. In various embodiments, the tubular element 32080 in thetissue thickness compensator 32080 can extend longitudinally throughsuccessive staple entrapment areas 30039. In such an arrangement, thetubular element 32080 can be deformed to different deformedconfigurations in each staple entrapment area 30039 along a row of firedstaples 30030. Referring now to FIG. 89, tubular elements 33080 in atissue thickness compensator 33020 can be laterally arranged in thestaple entrapment areas 30039 along a row of fired staples 30030. Invarious embodiments, the tubular elements 33080 can be retained by aflexible shell 33210. In such arrangements, the tubular elements 33080and flexible shell 33210 can be deformed to different deformedconfigurations in each staple entrapment area 30039. For example, wherethe tissue T is thinner, the tubular elements 33080 can be compressedless and where the tissue T is thicker, the tubular elements 33080 canbe compressed more to accommodate the thicker tissue T. In otherembodiments, the deformed dimensions of the tubular elements 33080 canbe uniform throughout the entire length and/or width of the tissuethickness compensator 33020.

Referring to FIGS. 90-92, in various embodiments, a tubular element34080 in a tissue thickness compensator 34020 can comprise a pluralityof strands 34090. Referring primarily to FIG. 90, in some embodiments,the strands 34090 can be woven or braided into a tubular lattice 34092forming the tubular element 34080. The tubular lattice 34092 formed bythe strands 34090 can be substantially hollow. The strands 34090 of thetubular element 34080 can be solid strands, tubular strands, and/oranother other suitable shape. For example, referring to FIG. 91, asingle strand 34090 of the tubular lattice 34092 can be a tube. Invarious embodiments, referring to FIG. 93, a strand 34090 can compriseat least one lumen 34094 extending therethrough. The number, geometryand/or dimensions(s) of the lumens 34094 can determine thecross-sectional shape of the strand 34090. For example, a strand 34090can comprise circular lumen(s), semi-circular lumen(s), wedge-shapedlumen(s), and/or combinations thereof. In various embodiments, a strand34090 can also comprise support webs 34096 that can form a modified “T”or “X” shape, for example. At least the diameter of the strand 34090,the lumen(s) extending therethrough, and the support web(s) cancharacterize the cross-sectional shape of a strand 34090. Thecross-sectional shape of each strand 34090, as discussed in greaterdetail herein, can affect the springback or restoring force generated bythe strand 34090 and the corresponding springback or restoring forcegenerated by the tubular element 34080.

Referring to FIG. 94, a tubular lattice 34092 of strands 34090 can bedeformable. In various embodiments, the tubular lattice 34092 canproduce or contribute to the deformability and/or the resiliency of thetubular element 34080. For example, the strands 34090 of the tubularlattice 34092 can be woven together such that the strands 34090 areconfigured to slide and/or bend relative to each other. When a force isapplied to the elongate portion 34082 of the tubular element 34080, thestrands 34090 therein may slide and/or bend such that the tubularlattice 34092 moves to a deformed configuration. For example, referringstill to FIG. 94, a staple 30030 can compress the tubular lattice 34092and the tissue T captured in a staple entrapment area 34039 which cancause the strands 34090 of the tubular lattice 34092 to slide and/orbend relative to each other. A top apex 34086 of the tubular lattice34092 can move towards a bottom apex 34088 of the tubular lattice 34092when the tubular lattice 34092 is compressed to the deformedconfiguration in order to accommodate the captured tissue T in a stapleentrapment area 30039. In various circumstances, the tubular lattice34092 captured in a fired stapled 30030 will seek to regain itsundeformed configuration and can apply a restoring force to the capturedtissue T. Further, the portions of the tubular lattice 34092 positionedbetween staple entrapment areas 30039, i.e., not captured within a firedstaple 30030, can also be deformed due to the deformation of adjacentportions of the tubular lattice 34092 that are within the stapleentrapment areas 30039. Where the tubular lattice 34092 is deformed, thetubular lattice 34092 can seek to rebound or partially rebound from thedeformed configuration. In various embodiments, portions of the tubularlattice 34092 can rebound to their initial configurations and otherportions of the tubular lattice 34092 can only partially rebound and/orremain fully compressed.

Similar to the description of the tubular elements herein, each strand34090 can also be deformable. Further, deformation of a strand 34090 cangenerate a restoring force that depends on the resiliency of each strand34090. In some embodiments, referring primarily to FIGS. 91 and 92, eachstrand 34090 of a tubular lattice 34092 can be tubular. In otherembodiments, each strand 34090 of a tubular lattice 34092 can be solid.In still other embodiments, the tubular lattice 30092 can comprise atleast one tubular strand 34090, at least one solid strand 34090, atleast one “X”- or “T”-shaped strand 34090, and/or a combination thereof.

In various embodiments, the strands 34090 in the tubular element 34080can comprise a polymeric composition. The polymeric composition of astrand 34090 can comprise non-absorbable polymers, absorbable polymers,or combinations thereof. Examples of synthetic polymers include, but arenot limited to, polyglycolic acid (PGA), poly(lactic acid) (PLA),polycaprolactone (PCL), polydioxanone (PDO), and copolymers thereof. Insome embodiments, the absorbable polymers can include bioabsorbable,biocompatible elastomeric polymers, for example. Furthermore, thepolymeric composition of the strand 34090 can comprise syntheticpolymers, non-synthetic polymers, and/or combinations thereof. Invarious embodiments, similar to the polymeric compositions inembodiments described herein, the polymeric composition of the strand34090 can include varied amounts of absorbable polymers, non-absorbablepolymers, synthetic polymers, and/or non-synthetic polymers, forexample, by weight percentage.

The strands 34090 in the tubular element 34080 can further comprise atherapeutic agent 34098 (FIG. 91) such as a pharmaceutically activeagent or medicament, for example. In some embodiments, the strand 34090can release a therapeutically effective amount of the therapeutic agent34098. In various embodiments, the therapeutic agent 34098 can bereleased as the tubular strand 34090 is absorbed. For example, thetherapeutic agent 30098 can be released into fluid, such as blood forexample, passing over or through the strand 34090. In still otherembodiments, the therapeutic agent 34098 can be released when a staple30030 pierces the strand 34090 and/or when the cutting element 30052 onthe staple-firing sled 30050 (FIG. 84) cuts a portion of the tubularlattice 34092, for example. Examples of therapeutic agents 34098 caninclude, but are not limited to, haemostatic agents and drugs such as,for example, fibrin, thrombin, and/or oxidized regenerated cellulose(ORC), anti-inflammatory drugs such as, for example, diclofenac,aspirin, naproxen, sulindac, and/or hydrocortisone, antibiotic andantimicrobial drugs or agents such as, for example, triclosan, ionicsilver, ampicillin, gentamicin, polymyxin B, and/or chloramphenicol,anticancer agents such as, for example, cisplatin, mitomycin, and/oradriamycin; and/or biologics such as, for example, stem cells.

Referring to FIGS. 95 and 96, a tubular element 35080 can comprisemultiple layers 35100 of strands 35090. In some embodiments, the tubularelement 35080 can comprise multiple layers 35100 of tubular lattices35092. Referring to FIG. 95, the tubular element 35080 can comprise afirst layer 35100 a and a second layer 35100 b of strands 35090, forexample. Referring now to FIG. 96, a tubular element 35180 of a tissuethickness compensator 35120 can comprise a third layer 35100 c ofstrands 35090, for example. Furthermore, different layers 35100 in thetubular element 35180 can comprise different materials. In someembodiments, each layer 35100 a, 35100 b, 35100 c can be bioabsorbable,wherein, in at least one embodiment, each layer 35100 a, 35100 b, 35100c can comprise a different polymeric composition. For example, the firstlayer 35100 a can comprise a first polymeric composition; the secondlayer 35100 b can comprise a second polymeric composition; and the thirdlayer 35100 c can comprise a third polymeric composition. In suchembodiments, layers 35100 a, 35100 b, 35100 c of the tubular element35180 can be bioabsorbed at different rates. For example, the firstlayer 35100 a can absorb quickly, the second layer 35100 b can absorbslower than the first layer 35100 a, and the third layer 35100 c canabsorb slower than the first layer 35100 a and/or the second layer 35100b. In other embodiments, the first layer 35100 a can absorb slowly, thesecond layer 35100 b can absorb faster than the first layer 35100 a, andthe third layer 35100 c can absorb faster than the first layer 35100 aand/or the second layer 35100 b.

Similar to strands 34090 described herein, the strands 35090 in thetubular element 35180 can comprise a medicament 35098. In variousembodiments, referring again to FIG. 95, to control elusion or releaseof the medicament(s) 35098, the first layer 35100 a of strands 35090comprising a medicament 35098 a can be bioabsorbed at a first rate andthe second layer 35100 b of strands 35090 comprising a medicament 30098b can be bioabsorbed at a second rate. For example, the first layer35100 a can absorb quickly to allow for a rapid initial release of themedicament 35098 a and the second layer 35100 b can absorb slower toallow controlled release of the medicament 30098 b. The medicament 35098a in the strands 35090 of the first layer 30100 a can be different thanthe medicament 35098 b in the strands 35090 of the second layer 35100 b.For example, the strands 35090 in the first layer 35100 a can compriseoxidized regenerated cellulose (ORC) and the strands 35090 in the secondlayer 35100 b can comprise a solution comprising hyaluronic acid. Insuch embodiments, initial absorption of the first layer 35100 a canrelease oxidized regenerated cellulose to help control bleeding whilesubsequent absorption of the second layer 35100 b can release a solutioncomprising hyaluronic acid to can help prevent the adhesion of tissue.In other embodiments, the layers 35100 a, 35100 b can comprise the samemedicament 35098 a, 35098 b. For example, referring again to FIG. 96,strands 35090 in layers 35100 a, 35100 b and 35100 c can comprise ananticancer agent, such as, for example, cisplatin. Furthermore, thefirst layer 35100 a can absorb quickly to allow for a rapid initialrelease of cisplatin, the second layer 35100 b can absorb slower toallow for a controlled release of cisplatin, and the third layer 35100 ccan absorb slowest to allow for a more extended, controlled release ofcisplatin.

In various embodiments, referring to FIGS. 97 and 98, a tissue thicknesscompensator 36020 can comprise an overmold material 36024. The overmoldmaterial 36024 can be formed outside a tubular element 36080, inside atubular element 36080, or both inside and outside a tubular element36080. In some embodiments, referring to FIG. 97, the overmold material36024 can be coextruded both inside and outside the tubular element36080 and, in at least one embodiment, the tubular element 36080 cancomprise a tubular lattice 36092 of strands 36090. Similar to thepolymeric composition described herein, the overmold material 36024 cancomprise polyglycolic acid (PGA), poly(lactic acid) (PLA), and/or anyother suitable, bioabsorbable and biocompatible elastomeric polymers,for example. Further, the overmold material 36024 can be non-porous suchthat the overmold material 36024 forms a fluid-impervious layer in thetubular element 36080. In various embodiments, the overmold material36024 can define a lumen 36084 therethrough.

Further to the discussion above, the tubular element 36080 and/or thestrands 36090 in a tubular lattice 36092 can comprise a therapeuticagent 36098. In some embodiments, referring still to FIGS. 97 and 98, anon-porous overmold material 36024 can contain the medicament 36098within an inner lumen 36084 a. Alternatively or additionally, thenon-porous, overmold material 36024 can contain the medicament 36098within an intermediate lumen 36084 b, such as, for example, theintermediate lumen 36084 b that contains the tubular lattice 36092 ofmedicament-comprising strands 36090. Similar to the above, the tubularelement 36080 can be positioned relative to staple cavities 30012 and acutting element 30052 in staple cartridge 30000 (FIG. 84). In severalsuch embodiments, the deployment of the staples 30030 and/or thetranslation of the cutting element 30052 can be configured to pierce orrupture the non-porous, overmold material 36024 such that the medicament36098 contained in at least one lumen 36084 of the tubular element 30080can be released from the lumen 30084. In various embodiments, referringto FIG. 99, a tubular element 37080 can comprise a non-porous film37110. The non-porous film 37110 can at least partially surround atubular lattice 37092 or a first layer 37100 a and a second layer 37100b of tubular lattices 30092 to provide a fluid-impervious cover similarto the overmold material 36024 described herein.

As described herein, a tubular element can comprise at least one of abioabsorbable material, a therapeutic agent, a plurality of strands, atubular lattice, layers of tubular lattices, an overmold material, anon-porous film, or combinations thereof. For example, referring to FIG.FIG. 100, a tubular element 38080 can comprise an overmold material38024 and a plurality of strands 38090 positioned through a centrallumen 38084 of the tubular element 38080. In some embodiments, thestrands 38090 can comprise a therapeutic agent 38098. In otherembodiments, for example, referring to FIG. 101, a tubular element 39080can comprise an overmold material 39024 and a therapeutic agent 39098positioned in a central lumen 39084 of the tubular element 39080, forexample. In various embodiments, at least one of the tubular element39080 and overmold material 39024 can comprise a fluidic therapeuticagent 39098.

In various embodiments, referring again primarily FIG. 84, the tubularelement 30080 can be positioned relative to the rigid support portion30010 of the staple cartridge 30000. The tubular element 30080 can belongitudinally positioned adjacent to the rigid support portion 30010.In some embodiments, the tubular element 30080 can be substantiallyparallel to or aligned with a longitudinal slot or cavity 30015 in therigid support portion 30010. The tubular element 30080 can be alignedwith the longitudinal slot 30015 such that a portion of the tubularelement 30080 overlaps a portion of the longitudinal slot 30015. In suchembodiments, a cutting element 30052 on the staple-firing sled 30050 cansever a portion of the tubular element 30080 as the cutting edge 30052translates along the longitudinal slot 30015. In other embodiments, thetubular element 30080 can be longitudinally positioned on a first orsecond side of the longitudinal slot 30015. In still other embodiments,the tubular element 30080 can be positioned relative to the rigidsupport portion 30010 of the staple cartridge 30000 such that thetubular element 30080 laterally or diagonally traverses at least aportion of the rigid support portion 30010.

In various embodiments, referring to FIG. 102 for example, a tissuethickness compensator 40020 can comprise multiple tubular elements40080. In some embodiments, the tubular elements 40080 can comprisedifferent lengths, cross-sectional shapes, and/or materials, forexample. Further, the tubular elements 40080 can be positioned relativeto the rigid support portion 40010 of the staple cartridge 30000 suchthat the tubular axes of the tubular elements 40080 are parallel to eachother. In some embodiments, the tubular axes of tubular elements 40080can be longitudinally aligned such that a first tubular element 40080 ispositioned within another tubular element 40080. In other embodiments,parallel tubular elements 40080 can longitudinally traverse the staplecartridge 30000, for example. In still other embodiments, paralleltubular elements 40080 can laterally or diagonally traverse the staplecartridge 30000. In various other embodiments, non-parallel tubularelements 40080 can be angularly-oriented relative to each other suchthat their tubular axes intersect and/or are not parallel to each other.

Referring to FIGS. 102-105, a tissue thickness compensator 40020 canhave two tubular elements 40080; a first tubular element 40080 a can belongitudinally positioned on a first side of the longitudinal slot 30015in the rigid support portion 30010 and a second tubular element 40080 bcan be longitudinally positioned on a second side of the longitudinalslot 30015. Each tubular element 40080 can comprise a tubular lattice40092 of strands 40090. In various embodiments, the staple cartridge30000 can comprise a total of six rows of staple cavities 30012, whereinthree rows of staple cavities 30012 are positioned on each side of thelongitudinal slot 30015, for example. In such embodiments, the cuttingedge 30052 on the translating staple-firing sled 30050 may not berequired to sever a portion of the tubular element 40080.

Similarly, referring now to FIGS. 106-107, a tissue thicknesscompensator 41020 can comprise two tubular elements 41080 a, 41080 blongitudinally arranged in the staple cartridge 30000. Similar to theabove, staples 30030 from three rows of staple cavities 30012 can engageone tubular element 41080 a and staples 30030 from three different rowsof staple cavities 30012 can engage another tubular element 41080 b. Invarious embodiments, referring still to FIGS. 106-107, deployed staples30030 can engage the tubular element 40080 at different locations acrossthe cross-section of the tubular element 40080. As discussed herein, thespringback resiliency and corresponding restoring force exerted by thetubular element 41080 can depend on the cross-sectional shape of thetubular element 41080, among other things. In some embodiments, a staple30030 positioned in a staple entrapment area 30039 located at or near anarced portion of the tubular element 41080 can experience a greaterrestoring force than a staple 30030 in a staple entrapment area 30039positioned near a non-arced portion. Similarly, a staple 30030positioned in staple entrapment area 30039 in the non-arced portion ofthe tubular element 41080 can experience a lesser restoring force thanthe restoring force experienced by a staple 30030 positioned at ornearer to the arced portion of the tubular element 30080. In otherwords, the arced portions of a tubular element 41080 can have a greaterspring rate than the non-arced portion of the tubular element 41080owing to the possibility that a larger quantity of elastic material maybe captured by the staples 30030 along such portions. In variousembodiments, as a result, referring primarily to FIG. 107, the restoringforce generated by the tissue thickness compensator 41020 can be greaternear staples 30030 a and 30030 c and less near staple 30030 b in tubularelement 30080 a. Correspondingly, the restoring force generated by thetissue thickness compensator 41020 can be greater near staples 30030 dand 30030 f than near staple 30030 e in tubular element 30080 b.

Referring again to FIGS. 102-105, in various embodiments, thecross-sectional geometries of strands 40090 comprising the tubularlattice 40092 can be selected in order to provide a desired springbackresiliency and corresponding restoring force exerted by the tubularlattice 40092. For example, referring again to FIG. 103, strands 40090 apositioned in arced portions of the tubular element 40080 can compriseX-shaped cross-sections, whereas strands 40090 b positioned in non-arcedportions of the tubular element 40080 can comprise tubularcross-sections. In some embodiments, strands 40090 a and 40090 bcomprising different cross-sectional geometries can be woven together toform the tubular lattice 40092. In other embodiments, the strands 40090a and 40090 b can be attached to one another with an adhesive, forexample. Referring to FIGS. 104 and 105, the different cross-sectionalgeometries of strands 40090 in the tubular element 40080 can optimizethe restoring force experienced in staple entrapment areas 30039 acrossthe staple cartridge 30000. In some embodiments, specificcross-sectional geometries can be selected such that the springbackconstant in staple entrapment areas 30039 across the staple cartridge issubstantially balanced or equal.

In some embodiments, referring to FIG. 108, the tubular elements 41080a, 41080 b of a tissue thickness compensator 41120 can be fastenedtogether by an adjoining portion 41126. Though the translating cuttingelement 30052 can be configured to pass between tubular elements 41080 aand 41080 b, the cutting element 30052 can be required to sever at leasta portion of the adjoining portion 41126. In some embodiments, theadjoining portion 41126 can comprise a soft material, such as, forexample, a foam or gel, which is easily severed by the translatingcutting element 30052. In various embodiments, the adjoining portion41026 can releasably secure the tissue thickness compensator 41120 tothe surgical end effector 12. In at least one embodiment, the adjoiningportion 41126 can be fixed to the top deck surface 30011 of the rigidsupport portion 30010 such that the adjoining portion 41126 remainsretained in the surgical end effector 12 after the tubular elements41080 a, 41080 b are released therefrom.

In various embodiments, referring to FIGS. 109-110, a tissue thicknesscompensator 42020 can comprise multiple tubular elements 42080 such thatthe number of tubular elements 42080 is the same as the number of rowsof staple cavities 30012 in the staple cartridge 30000, for example. Inat least one embodiment, the staple cartridge 30000 can comprise sixrows of staple cavities 30012 and the tissue thickness compensator 42020can comprise six tubular elements 42080. Each tubular element 42080 canbe substantially aligned with a row of staple cavities 30012. Whenstaples 30030 are ejected from a row of staple cavities 30012, eachstaple 30030 from that row can pierce the same tubular element 42080(FIG. 110). In various embodiments, the deformation of one tube 42080can have little or no impact on the deformation of an adjacent tube42080. Accordingly, the tubular elements 42080 can exert a substantiallydiscrete and customized springback force in staple entrapment areas30039 across the width of the staple cartridge 30030. In someembodiments, where staples 30030 fired from multiple rows of staplecavities 30012 engage the same tubular element 35080 (FIG. 107), thedeformation of the tubular element 35080 can be less customized. Forexample, the deformation of a tubular element 35080 in a stapleentrapment area 30039 in a first row can impact the deformation of thattubular element 35080 in staple entrapment area 30039 in another row. Inat least one embodiment, the translating cutting edge 30052 can avoidsevering the tubular elements 42080. In other embodiments, referring toFIG. 111, a tissue thickness compensator 43020 can comprise more thansix tubular elements 43080, such as, for example, seven tubular elements44080. Further, the tubular elements 43080 can be symmetrically ornon-symmetrically arranged in the end effector 12. When an odd number oftubular elements 43080 are longitudinally and symmetrically arranged inthe end effector 12, the translating cutting element 30052 can beconfigured to sever the middle tubular element that overlies thelongitudinal channel 30015.

In various embodiments, referring to FIG. 112, a tissue thicknesscompensator 44020 can comprise a central tubular element 44080 b that isat least partially aligned with the longitudinal slot 30015 in the rigidsupport portion 33010 of the staple cartridge 30000. The tissuethickness compensator 44020 can further comprise at least one peripheraltubular element 44080 a, 44080 c located on a side of the longitudinalslot 30015. For example, the tissue thickness compensator 44020 cancomprise three tubular elements 44080: a first peripheral tubularelement 44080 a can be longitudinally positioned on a first side of thelongitudinal slot 30015 of the staple cartridge 30000, a central tubularelement 44080 b can be substantially positioned over and/or aligned withthe longitudinal slot 30015, and a second peripheral tubular element44080 c can be longitudinally positioned on a second side of thelongitudinal slot 30015. In some embodiments, the central tubularelement 44080 b can comprise a horizontal diameter that is substantiallyelongated relative to the vertical diameter. In various embodiments, thecentral tubular element 44080 b, and/or any other tubular element, canoverlap multiples rows of staple cavities 30012. Referring still to FIG.112, the central tubular element 44080 b can overlap four staple rows ofstaple cavities 30012 and each peripheral tubular element 44080 a, 44080c can overlap a single row of staple cavities 30012, for example. Inother embodiments, the central tubular element 44080 b can overlap lessthan four rows of staple cavities 30012, such as, for example, two rowsof staple cavities 30012, for example. Further, peripheral tubularelements 44080 a, 44080 c can overlap more than one row of staplecavities 30012, such as, for example, two rows of staple cavities 30012.Referring now to FIG. 113, a central tubular element 44180 b of a tissuethickness compensator 44120 can comprise a therapeutic agent 44198 in alumen 44184 of the central tubular element 44180 b. In variousembodiments, central tubular element 44180 b and/or at least oneperipheral tubular element 44080 a, 44080 c can comprise the therapeuticagent 44198 and/or any other suitable therapeutic agent.

In various embodiments, referring to FIG. 114, the tissue thicknesscompensator 44220 can comprise a shell 44224, which can be similar toovermold material 32024 described herein. In various embodiments, theshell 44224 retains multiple tubular elements 44080 in position in theend effector 12. The shell 44224 can be coextruded with the tubularelements 44080. In some embodiments, the tubular elements 44080 cancomprise a tubular lattice 44092 of strands 44090. Similar to thepolymeric compositions described in embodiments herein, the shell 44224can comprise polyglycolic acid (PGA), poly(lactic acid) (PLA), and/orany other suitable bioabsorbable, biocompatible elastomeric polymers,for example. Further, the shell 44224 can be non-porous such that theshell 44224 forms a fluid-impervious layer in the tissue thicknesscompensator 44220, for example. Further to the discussion herein, thetubular element 44080 and/or the strands 44090 in the tubular lattice44092 can comprise a therapeutic agent 44098. In some embodiments, thenon-porous shell 44224 can contain the therapeutic agent 44098 withinthe tissue thickness compensator. As described herein, the tubularelement 44080 can be positioned relative to staple cavities 30012 and acutting element 30052 in staple cartridge 30000. In several suchembodiments, deployment of the staples 30030 and/or translation of thecutting element 30052 can be configured to pierce or rupture thenon-porous, shell 44224 such that the therapeutic agent 44198 containedtherein can be released from the tissue thickness compensator 44020.

Referring to FIG. 115, a tissue thickness compensator 44320 can comprisea central tubular element 44380 b comprising a tubular lattice 44392.The tubular lattice 44392 can have a non-woven portion or a gap 44381that is substantially aligned with the longitudinal slot 30015 of therigid support portion 30010. In such embodiments, a woven portion of thetubular lattice 44092 of the tubular element 44380 b does not overlapthe longitudinal slot 30015. Accordingly, the cutting element 30052 onthe translating staple-fire sled 30052 can translate along thelongitudinal slot 30015 without severing an overlapping a woven portionof the tubular lattice 44392. Though staples 30030 c and 30030 dpositioned adjacent to the gap 44381 in tubular element 44380 b mayreceive less support from the tubular lattice 44392 structure, in someembodiments, additional features can provide support for those staples30030 and/or additional restoring force in the staple entrapment areas30039 thereof. For example, as described in greater detail herein,additional tubular elements, support webbing, springs and/or buttressingmaterial can be positioned at least one of inside and outside tubularelement 44380 b near gap 44381, for example.

Referring now to FIGS. 116-119, in various embodiments, a tissuethickness compensator 45020 can comprise multiple tubular elements 45080that laterally traverse the staple cartridge 30000. The tubular elements45080 can be positioned perpendicular to the rows of staple cavities30012 and/or the longitudinal axis of the rigid support portion 30010 ofthe staple cartridge 30000. In some embodiments, referring to FIG. 116,the tubular elements 45080 can traverse the longitudinal slot 30015 inthe staple cartridge 30000 such that the cutting element 30052 on thestaple-firing sled 30050 is configured to sever the tubular elements45080 as the staple-firing sled 30050 translates along the longitudinalslot 30015. In other embodiments, referring now to FIG. 117, the tissuethickness compensator 46020 can comprise two sets of laterallytraversing tubular elements 46080. The first set of laterally traversingtubular elements 46080 a can be positioned on a first side of thelongitudinal slot 30015 and the second set of laterally traversingtubular elements 46080 b can be positioned on a second side of thelongitudinal slot 30015. In such an arrangement, the cutting element30052 can be configured to pass between the two sets of tubular elements46080 without severing a portion of the tubular elements 46080. In otherembodiments, the cutting element 30052 can sever at least one tubularelement 46080 that traverses the longitudinal slot 30015 while at leastone other tubular element 46080 does not traverse the longitudinal slot30015 and is not severed by the cutting element 30052.

As the tubular elements 45080 laterally traverse the staple cartridge30000, referring to FIGS. 118 and 119, a staple 30030 can engage atleast one tubular element 45080 in each staple entrapment area 30039. Insuch an arrangement, each tubular element 45080 can provide a discreterestoring force along the length of the staple cartridge 30000. Forexample, referring primarily to FIG. 119, the tubular elements 45080positioned near the proximal end of the tissue thickness compensator45020 where the tissue is thicker can be greatly compressed compared tothe tubular elements 45080 positioned near to the distal end of thetissue thickness compensator 45020 where the tissue is thinner. As aresult, the tubular elements 45080 positioned closer to the proximal endof the tissue thickness compensator 45020 can provide a greaterrestoring force than the restoring force that could be generated by thetubular elements 46080 positioned closer to the distal end of the tissuethickness compensator 45020. Further, referring still to FIG. 119, thedeformation of one tube 45080 can have little or no impact on thedeformation of an adjacent tube 45080. Accordingly, the tubular elements45080 can exert a substantially discrete and customized springback forcein staple entrapment areas 30039 along the length of the staplecartridge 30030. In some embodiments, where multiple staples 30030 firedfrom a single row of staple cavities 30012 engage the same tubularelement 35080, the deformation of the tubular element 35080 can be lesscustomized. For example, the deformation of a tubular element 35080 inone staple entrapment area 30039 can impact the deformation of thattubular element 35080 in another staple entrapment area 30039.

In still other embodiments, referring to FIGS. 120-125, tubular elements47080 of the tissue thickness compensator 47020 can diagonally traversethe staple cartridge 30000. The tubular elements 47080 can traverse thelongitudinal slot 30015 of the staple cartridge 30000 such that thecutting element 30052 on the staple-firing sled 30050 is configured tosever the diagonally traversing tubular elements 47080 as thestaple-firing sled 30052 translates along the longitudinal slot 30015.In other embodiments, the tissue thickness compensator 47020 cancomprise two sets of diagonally traversing tubular elements 47080. Afirst set of diagonally traversing tubular elements 47080 can bepositioned on a first side of the longitudinal slot 30015 and a secondset of diagonally traversing tubular elements 47080 can be positioned ona second side of the longitudinal slot 30015. In such an arrangement,the cutting element 30052 can pass between the two sets of tubularelements 47080 and may not sever any tubular element 47080.

Referring still to FIGS. 120-123, the diagonally traversing tubularelements 47080 can be positioned in the staple cartridge 30000 such thata gap is defined between the tubular elements 47080. A gap betweenadjacent tubular elements 47080 can provide space for horizontalexpansion of the tubular elements 47080 when a compressive force isapplied thereto, such as, for example, by tissue T captured within thestaple entrapment area 30039 of the formed staple 30030. The tubularelements 47080 can be connected across a gap by a film or sheet ofmaterial 47024. The sheet of material can be positioned on at least oneof the deck surface 30011 of the rigid support portion 30010 and/or thetissue contacting side of the tubular elements 47080.

In various embodiments, referring to FIGS. 124 and 125, at least onediagonally traversing tubular element 47080 can be positioned relativeto the staple cavities 30012 in the staple cartridge 30000 such that thetubular element 47080 is positioned between the legs 30032 of thestaples 30030 deployed from multiple rows of staple cavities 30012. Asthe staples 30030 are moved from the initial position to the firedposition, as described in greater detail herein, the staple legs 30032can remain positioned around the tubular element 47080. Further, thestaples can be deformed such that the staple legs 30032 wrap around theperimeter of the tubular element 47080, for example. In such anarrangement, the staples 30030 can be configured to move to the fired orformed position without piercing the tubular element 47080. Movement ofthe staple legs 30032 around the tubular element 47080 could in someembodiments, prevent the inadvertent release of a therapeutic agent47098 retained therein. The selected angular orientation of each tubularelement 47080 relative to the longitudinal slot 30015 of the staplecartridge 30000 can depend on the position of the staple cavities 30012in the staple cartridge 30000. For example, in some embodiments, thetubular elements 47080 can be positioned at an approximately forty-five(45) degree angle relative to the longitudinal slot 30015 of the staplecartridge 30000. In other embodiments, the tubular elements 47080 can bepositioned at a fifteen (15) to seventy-five (75) degree angle relativeto the longitudinal slot 30015 of the staple cartridge 30000, forexample.

Similar to descriptions throughout the present disclosure, multipletubular elements in a tissue thickness compensator can be connected by abinding agent, wrap, webbing, overmold, compensation material, and/orany other suitable connecting adhesive or structure, for example. Invarious embodiments, referring to FIGS. 126-128, a flexible shell 48024may surround or encapsulate tubular elements 48080 in a tissue thicknesscompensator 48020. In various embodiments, the flexible shell 48024 canrestrain the tubular elements 48080 in the end effector 12 and can holdeach tubular element 48080 in position, such as, for example, inlongitudinal alignment with a row of staple cavities 30012. In at leastone embodiment, the tissue thickness compensator 48020 can comprise sixtubular elements 48080, for example. In various embodiments, theflexible shell 48024 can be sufficiently deformable and resilient torestrain the tubular elements 48020 encased therein while permittingdeformation and rebound of the tubular elements 48080. Further, in someembodiments, the flexible shell 48024 can tautly surround the tubularelements 48080 and can remain tautly engaged with the tubular elements48080 as they deform and/or rebound.

Referring to FIG. 127, prior to the deployment of staples 30030, theanvil 30060 can be pivoted or rotated downwardly to compress the tissuethickness compensator 48020 and tissue T between the anvil 30060 and thestaple cartridge 30000. Compression of the tissue thickness compensator48020 can include a corresponding compression of the flexible shell48024 and the tubular elements 48020 therein. As the tubular elements48020 deform, the flexible shell 48024 can similarly deform. In variousembodiments, the tubular elements 48020 can be uniformly compressedacross the width of the staple cartridge 30000 and the flexible shell48024 can experience a similarly uniform compression across the tubularelements 48080. Referring to FIG. 128, when the anvil 30060 is openedafter the staples 30030 have been deployed from the staple cartridge30000, the tubular elements 48080 can rebound or partially rebound fromthe compressed configurations (FIG. 127). In various embodiments, atubular element 48080 can rebound such that the tubular element 48080returns to its initial, undeformed configuration. In some embodiments, atubular element 48080 can partially rebound such that the tubularelement 48080 partially returns to its initial undeformed configuration.For example, the deformation of the tubular element 48080 can bepartially elastic and partially plastic. As the tubular elements 48080rebound, the flexible shell 48024 can remain tautly engaged with eachtubular element 48080. The tubular elements 48080 and flexible shell48024 can rebound to such a degree that the tubular elements 48080 andtissue T fill the staple entrapment areas 30039 while the tubularelements 48080 exert an appropriate restoring force on the tissue Ttherein. Referring to FIG. 129, in other embodiments, a tissue thicknesscompensator 48120 comprising six tubular elements 48180 retained in aflexible shell 48124 can be positioned on the anvil 30060 of the endeffector 12, for example.

Referring to FIGS. 130-133, a tissue thickness compensator 49020 cancomprise a tubular element 49080 longitudinally positioned along thelongitudinal axis of the anvil 30060. In various embodiments, the tissuethickness compensator 49020 can be secured to the anvil 30060 of the endeffector 12 by a compressible compensation material 49024. Further, thecompressible compensation material 49024 can surround or encapsulate thetubular element 49080. Similar to the descriptions herein, the tubularelement 49080 can comprise at least one therapeutic agent 49098 whichmay be released by the absorption of various components of the tissuethickness compensator 49020, the piercing of the tubular element 49080by staples 30030 fired from the staple cartridge 30000, and/or by thecutting element 30052.

Referring to FIG. 131, a staple cartridge 30000 can comprise staples30030 positioned in staple cavities 30012, wherein, prior to deploymentof the staples 30030, the anvil 30060 and the tissue thicknesscompensator 49020 attached thereto can pivot toward the staple cartridge30000 and compress tissue T captured therebetween. In some embodiments,the tubular element 49080 of the tissue thickness compensator 49020 canbe uniformly deformed along the length of the staple cartridge 30000 bythe pivoting anvil 30060 (FIG. 131). Referring to FIGS. 132 and 133, thestaple-firing sled 30050 can translate along the longitudinal slot 30015in the staple cartridge 30000 and engage each driver 30040 positionedbeneath a staple 30030 in a staple cavity 30010, wherein each engageddriver 30040 can fire or eject the staple 30030 from the staple cavity30012. When the anvil 30060 releases pressure on the tissue T and thetissue thickness compensator 49020, the tissue thickness compensator49020, including the tubular element 49080 and the compressiblecompensation material 49024, can rebound or partially rebound from thecompressed configurations (FIG. 131) to a rebounded configuration (FIGS.132 and 133). The tubular element 49080 and compressible compensationmaterial 49024 can rebound to such a degree that the tissue thicknesscompensator 49020 and tissue T fill the staple entrapment areas 30039while the tissue thickness compensator 49020 exert an a restoring forceon the captured tissue T.

In various embodiments, referring to FIGS. 124-126, two tissue thicknesscompensators 50020 a, 50020 b can be positioned in the end effector 12of a surgical instrument. For example, a first tissue thicknesscompensator 50020 a can be attached to the staple cartridge 30000 in thelower jaw 30070 and a second tissue thickness compensator 50020 b can beattached to the anvil 30060. In at least one embodiment, the firsttissue thickness compensator 50020 a can comprise a plurality of tubularelements 50080 longitudinally arranged and retained in a firstcompensation material 50024 a. At least one tubular element 50080 cancomprise a therapeutic agent 50098, similar to the therapeutic agentsdescribed herein. The first compensation material 50024 a can bedeformable or substantially rigid. Further, in some embodiments, thefirst compensation material 50024 a can hold the tubular elements 50080in position relative to the staple channel 30000. For example, the firstcompensation material 50024 a can hold each tubular element 50080 inlongitudinal alignment with a row of staple cavities 30012. In at leastone embodiment, the second tissue thickness compensator 50020 b cancomprise the first compensation material 50024 a, a second compensationmaterial 50024 b and/or a third compensation material 50024 c. Thesecond and third compensation material 50024 b, 50024 c can bedeformable or substantially rigid.

Similar to at least one embodiment described herein, the anvil 30060 canpivot and apply a compressive force to the tissue thickness compensators50020 a, 50020 b and the tissue T between the anvil 30060 and the staplecartridge 30000. In some embodiments, neither the first tissue thicknesscompensators 50020 a nor the second tissue thickness compensators 50020b can be compressible. In other embodiments, at least one component ofthe first tissue thickness compensators 50020 a and/or the second tissuethickness compensators 50020 b can be compressible. When the staples30030 are fired from the staple cartridge 30000, referring now to FIGS.135 and 136, each staple 30030 can pierce a tubular element 50080retained in the first tissue thickness compensator 50020 a. As shown inFIG. 135, the therapeutic agent 50098 retained in the tubular element50080 can be released when a staple 30030 pierces the tubular element50080. When released, the therapeutic agent 50098 can coat the staplelegs 30032 and tissue T surrounding the fired staple 30030. In variousembodiments, the staples 30030 can also pierce the second tissuethickness compensator 50020 b when the staples 30030 are fired from thestaple cartridge 30000.

Referring to FIGS. 137-140, a tissue thickness compensator 51020 cancomprise at least one tubular element 51080 that laterally traverses thetissue thickness compensator 51020. For example, referring to FIG. 137,the tissue thickness compensator 51020 can be positioned relative to thestaple cartridge 30000 such that a first end 51083 of the laterallytraversing tubular element 51080 can be positioned near a firstlongitudinal side of the staple cartridge 30000 and a second end 51085of the laterally traversing tubular element 51080 can be positioned neara second longitudinal side of the staple cartridge 30000. In variousembodiments, the tubular element 51080 can comprise a capsule-likeshape, for example. As illustrated in FIG. 138, the tubular element51080 can be perforated between the first end 51083 and the second end51085 and, in some embodiments, the tubular element 51080 can beperforated at or near the center 51087 of the tubular element 51080. Thetubular element 51080 can comprise a polymeric composition, such as abioabsorbable, biocompatible elastomeric polymer, for example. Further,referring again to FIG. 137, the tissue thickness compensator 51020 cancomprise a plurality of laterally traversing tubular elements 51080. Inat least one embodiment, thirteen tubular elements 51080 can belaterally arranged in the tissue thickness compensator 51020, forexample.

Referring again to FIG. 137, the tissue thickness compensator 51020 canfurther comprise a compensation material 51024 that at least partiallysurrounds the tubular elements 51080. In various embodiments, thecompensation material 51024 can comprise a bioabsorbable polymer, suchas, for example, lyophilized polysaccharide, glycoprotein, elastin,proteoglycan, gelatin, collagen, and/or oxidized regenerated cellulose(ORC). The compensation material 51024 can hold the tubular elements51080 in position in the tissue thickness compensator 51020. Further,the compensation material 51024 can be secured to the top deck surface30011 of the rigid support portion 30010 of the staple cartridge 30000such that the compensation material 51020 is securely positioned in theend effector 12. In some embodiments, the compensation material 51024can comprise at least one medicament 51098.

Still referring to FIG. 137, laterally positioned tubular elements 51080can be positioned relative to the translating cutting element 30052 suchthat the cutting element 30052 is configured to sever the tubularelements 51080. In various embodiments, the cutting element 30052 cansever the tubular elements 51080 at or near the perforation therein.When the tubular elements 51080 are severed in two halves, the severedportions of the tubular elements 51080 can be configured to swell orexpand, as illustrated in FIG. 139. For example, in various embodiments,the tubular element 51080 can comprise a hydrophilic substance 51099that can be released and/or exposed when the tubular element 51080 issevered. Furthermore, when the hydrophilic substance 51099 contactsbodily fluids in tissue T, the hydrophilic substance 51099 can attractthe fluid, which can cause the tubular element 51080 to swell or expand.As the tubular element 51080 expands, the compensation material 51024surrounding the tubular element 51080 can shift or adjust to accommodatethe swollen tubular element 51080. For example, when the compensationmaterial 51024 comprises gelatin, the gelatin can shift to accommodatethe swollen tubular elements 51080. Referring now to FIG. 140, expansionof the tubular elements 51080 and shifting of the compensation material51024 can cause a corresponding expansion of the tissue thicknesscompensator 51020.

Similar to other tissue thickness compensators discussed throughout thepresent disclosure, the tissue thickness compensator 51020 can bedeformed or compressed by an applied force. Further, the tissuethickness compensator 51020 can be sufficiently resilient such that itproduces a springback force when deformed by the applied force and cansubsequently rebound or partially rebound when the applied force isremoved. In various embodiments, when the tissue thickness compensator51020 is captured in a staple entrapment area 30039, the staple 30030can deform the tissue thickness compensator 51020. For example, thestaple 30030 can deform the tubular elements 51080 and/or thecompensation material 51024 of the tissue thickness compensator 51020that are captured within the fired staple 30030. In various embodiments,non-captured portions of the tissue thickness compensator 51020 can alsobe deformed due to the deformation in the staple entrapment areas 30039.When deformed, the tissue thickness compensator 51020 can seek torebound from the deformed configuration. In various embodiments, such arebound may occur prior to the hydrophilic expansion of the tubularelement 51080, simultaneously with the hydrophilic expansion of thetubular element 51080, and/or after the hydrophilic expansion of thetubular element 51080. As the tissue thickness compensator 51020 seeksto rebound, it can exert a restoring force on the tissue also capturedin the staple entrapment area 30039, as described in greater detailherein.

In various embodiments, at least one of the tubular elements 51080and/or the compensation material 51024 in the tissue thicknesscompensator 51020 can comprise a therapeutic agent 51098. When thetubular element 51080 that contains a therapeutic agent 51098 issevered, the therapeutic agent 51098 contained within the tubularelements 51080 can be released. Furthermore, when the compensationmaterial 51024 comprises the therapeutic agent 51098, the therapeuticagent 51098 can be released as the bioabsorbable compensation material51024 is absorbed. In various embodiments, the tissue thicknesscompensator 51020 can provide for a rapid initial release of thetherapeutic agent 51098 followed by a controlled release of thetherapeutic agent 51098. For example, the tissue thickness compensator51020 can provide a rapid initial release of the therapeutic agent 51098from the tubular elements 51080 to the tissue T along the cut line whenthe tubular elements 51080 comprising the therapeutic agent 51098 aresevered. Further, as the bioabsorbable compensation material 51024comprising the therapeutic agent 51098 is absorbed, the tissue thicknesscompensator 51020 can provide an extended, controlled release of thetherapeutic agent 51098. In some embodiments, at least some of thetherapeutic agent 51098 can remain in the tubular element 51080 for ashort period of time before the therapeutic agent 51098 flows into thecompensation material 51024. In other embodiments, at least some of thetherapeutic agent 51098 can remain in the tubular element 51080 untilthe tubular element 51080 is absorbed. In various embodiments, thetherapeutic agent 51098 released from the tubular element 51080 and thecompensation material 51024 can be the same. In other embodiments, thetubular element 51080 and the compensation material 51024 can comprisedifferent therapeutic agents or different combinations of therapeuticagents, for example.

Referring still to FIG. 140, in various embodiments, the end effector 12can cut tissue T and fire staples 30030 into the severed tissue T nearlysimultaneously or in quick succession. In such embodiments, a staple30030 can be deployed into the tissue T immediately after the cuttingelement 30052 has severed the tubular element 51080 adjacent to thetissue T. In other words, the staples 30030 can engage the tissuethickness compensator 51020 immediately following or simultaneously withthe swelling of the tubular element 51080 and the expansion of thetissue thickness compensator 51020. In various embodiments, the tissuethickness compensator 51020 can continue to grow or expand after thestaples 30030 have been fired into the tissue T. In various embodiments,the staples 30030 can be configured to puncture the tubular elements51080 when the staples 30030 are deployed. In such embodiments,therapeutic agents 51098 still retained in the severed tubular elements51080 can be released from the tubular elements 51080 and, in someembodiments, can cover the legs 30031 of the fired staples 30030.

Referring to FIG. 141, the tissue thickness compensator 51020 can bemanufactured by a molding technique, for example. In variousembodiments, a frame, or a mold, 51120 can comprise a first longitudinalside 51122 and a second longitudinal side 51124. Each longitudinal side51124 can comprise one or more notches 51130, which can each beconfigured to receive the first or second end 50183, 50185 of a tubularelement 51080. In some embodiments, the first end 50183 of the tubularelement 51080 can be positioned in a first notch 51130 a on the firstlongitudinal side 51122 and the second end 50183 of the tubular element51080 can be positioned in a second notch 51130 b on the secondlongitudinal side 51124 such that the tubular element 51080 laterallytraverses the frame 51120. In various embodiments, the notch 51180 cancomprise a semi-circular groove, which can securely fit the first orsecond end 50183, 50185 of the tubular element 51080 therein. In variousembodiments, the first notch 51130 a can be positioned directly acrossfrom the second notch 51130 b and the tubular element 51080 can bepositioned perpendicular, or at least substantially perpendicular, tothe longitudinal axis of the frame 51120. In other embodiments, thefirst notch 51130 a can be offset from the second notch 51130 b suchthat the tubular element 51080 is angularly positioned relative to thelongitudinal axis of the frame 51120. In still other embodiments, atleast one tubular element 51080 can be longitudinally positioned withinthe frame 51120 such that the tubular element extends between thelateral sides 51126, 51128 of the frame 51120. Further, at least onetubular element can be angularly positioned in the frame between twonotches on the lateral sides 51126, 51128 of the frame and/or between anotch on a lateral side 51126 and a notch on a longitudinal side 51124,for example. In various embodiments, the frame 51120 can comprise asupport ledge 51136, which can support the tubular elements 51080positioned within the frame 51120.

In various embodiments, the frame 51120 can comprise notches 51130 toaccommodate twelve tubular elements 51080, for example. In someembodiments, the frame notches 51130 can be filled with tubular elements51080 while, in other embodiments, less than all of the notches 51130may be filled. In various embodiments, at least one tubular element51080 can be positioned in the frame 51120. In some embodiments, atleast half the notches 51130 can receive tubular elements 51080. In atleast one embodiment, once the tubular elements 51080 are positioned inthe frame 51120, compensation material 51024 can be added to the frame51120. The compensation material 51024 can be fluidic when added to theframe 51120. For example, in various embodiments, the compensationmaterial 51024 can be poured into the frame 51120 and can flow aroundthe tubular elements 51080 positioned therein. Referring to FIG. 142,the fluidic compensation material 51024 can flow around the tubularelement 51080 supported by notches 51130 in the frame 51120. After thecompensation material 51024 cures, or at least sufficiently cures,referring now to FIG. 143, the tissue thickness compensator 51020comprising the compensation material 51024 and tubular elements 51080can be removed from the frame 51120. In at least one embodiment, thetissue thickness compensator 51020 can be trimmed. For example, excesscompensation material 51024 can be removed from the tissue thicknesscompensator 51020 such that the longitudinal sides of the compensationmaterial are substantially planar. Furthermore, in some embodiments,referring to FIG. 144, the first and second ends 50183, 50185 of thetubular elements 51080 can be pressed together, or closed, to seal thetubular element 51080. In some embodiments, the ends can be closedbefore the tubular elements 51080 are placed in the frame 51120. Inother embodiments, the trimming process may transect the ends 51083,51085 and a heat stacking process can be used to seal and/or close theends 51083, 51085 of the tubular elements 51080.

In various embodiments, referring again to FIG. 141, a stiffening pin51127 can be positioned within each tubular element 51080. For example,the stiffening pin 51127 can extend through a longitudinal lumen of thetubular element 51080. In some embodiments, the stiffening pin 51127 canextend beyond each tubular element 51080 such that the stiffening pin51127 can be positioned in notches 51130 in the frame 51120. Inembodiments having stiffening pins 51127, the stiffening pins 51127 cansupport the tubular elements 51080 when the compensation material 51204is poured into the frame 51120 and as the fluidic compensation material51024 flows around the tubular elements 51080, for example. Once thecompensation material 51024 cures, solidifies, and/or lyophilizes orsufficiently cures, solidifies, and/or lyophilizes the tissue thicknesscompensator 51020 can be removed from the frame 51120 and the stiffeningpins 51127 can be removed from the longitudinal lumens of the tubularelements 51080. In some embodiments, the tubular elements 51080 can thenbe filled with medicaments, for example. Similar to at least oneembodiment described herein, after the tubular elements 51080 are filledwith medicaments, the tissue thickness compensator 51020, including theends 51083, 51085 of the tubular elements 51080, for example, can betrimmed. In various embodiments, the tissue thickness compensator 51020can be die cut, for example, and/or sealed by heat and/or pressure, forexample.

As discussed herein, the tissue thickness compensator 52020 can comprisemultiple tubular elements 51080. Referring now to FIG. 145, the tubularelements 51080 can comprise different material properties, dimensionsand geometries. For example, a first tubular element 51080 a cancomprise a first thickness and a first material and a second tubularelement 51080 b can comprise a second thickness and a second material.In various embodiments, at least two tubular elements 51080 in thetissue thickness compensator 52020 can comprise the same material. Inother embodiments, each tubular element 51080 in the tissue thicknesscompensator 5202 can comprise different materials. Similarly, in variousembodiments, at least two tubular elements 51080 in the tissue thicknesscompensator 52020 can comprise the same geometry. In other embodiments,each tubular element 51080 in the tissue thickness compensator 52020 cancomprise different geometries.

Referring now to FIGS. 208-211, a tissue thickness compensator 51220 cancomprise at least one tubular element 51280 that laterally traverses thetissue thickness compensator 51220. In various embodiments, referring toFIG. 208, the tissue thickness compensator 51220 can be positionedrelative to the anvil 30060 of the end effector 12. The tissue thicknesscompensator 51220 can be secured to a securing surface 30061 of theanvil 30060 of the end effector 12, for example. In various embodiments,referring primarily to FIG. 209, the tubular element 51280 can comprisea capsule-like shape, for example. The tubular element 51280 cancomprise a polymeric composition, such as a bioabsorbable, biocompatibleelastomeric polymer, for example.

Referring again to FIG. 208, the tissue thickness compensator 51220 canfurther comprise a compensation material 51224 that at least partiallysurrounds the tubular elements 51280. In various embodiments, thecompensation material 51224 can comprise a bioabsorbable polymer, suchas, for example, lyophilized polysaccharide, glycoprotein, elastin,proteoglycan, gelatin, collagen, and/or oxidized regenerated cellulose(ORC), for example. Similar to the above, the compensation material51024 can hold the tubular elements 51280 in position in the tissuethickness compensator 51220. Further, the compensation material 51224can be secured to the securing surface 30061 of the anvil 30060 suchthat the compensation material 51220 is securely positioned in the endeffector 12. In some embodiments, the compensation material 51224 cancomprise at least one medicant.

Still referring to FIG. 208, the laterally positioned tubular elements51280 can be positioned relative to the cutting element 30252 on atranslating sled 30250 such that the translatable cutting element 30252is configured to sever the tubular elements 51280. In variousembodiments, the cutting element 30252 can sever the tubular elements51280 at or near the center of each tubular element 51280, for example.When the tubular elements 51280 are severed in two halves, the severedportions of the tubular elements 51280 can be configured to swell orexpand, as illustrated in FIG. 208. Referring primarily to FIG. 210, invarious embodiments, a tubular element 51280 can comprise a hydrophilicsubstance 51099 that can be released and/or exposed when the tubularelement 51280 is severed. Furthermore, referring now to FIG. 211, whenthe hydrophilic substance 51099 contacts bodily fluids in the tissue T,the hydrophilic substance 51099 can attract the fluid, which can causethe tubular element 51280 to swell or expand. As the tubular element51280 expands, the compensation material 51224 surrounding the tubularelement 51280 can shift or adjust to accommodate the swollen tubularelement 51280. For example, when the compensation material 51224comprises gelatin, the gelatin can shift to accommodate the swollentubular element 51280. Referring again to FIG. 208, expansion of thetubular elements 51280 and shifting of the compensation material 51224can cause a corresponding expansion of the tissue thickness compensator51220.

Similar to other tissue thickness compensators discussed throughout thepresent disclosure, the tissue thickness compensator 51220 can bedeformed or compressed by an applied force. Further, the tissuethickness compensator 51220 can be sufficiently resilient such that itproduces a springback force when deformed by the applied force and cansubsequently rebound or partially rebound when the applied force isremoved. In various embodiments, when the tissue thickness compensator51220 is captured in a staple entrapment area 30039 (FIG. 88), thestaple 30030 can deform the tissue thickness compensator 51220. Forexample, the staple 30030 can deform the tubular elements 51280 and/orthe compensation material 51224 of the tissue thickness compensator51220 captured within the fired staple 30030. In various embodiments,non-captured portions of the tissue thickness compensator 51220 can alsobe deformed due to the deformation in the staple entrapment areas 30039.When deformed, the tissue thickness compensator 51220 can seek torebound from the deformed configuration. In various embodiments, such arebound may occur prior to the hydrophilic expansion of the tubularelement 51280, simultaneously with the hydrophilic expansion of thetubular element 51280, and/or after the hydrophilic expansion of thetubular element 51280. As the tissue thickness compensator 51220 seeksto rebound, it can exert a restoring force on the tissue also capturedin the staple entrapment area 30039, as described in greater detailherein.

Referring to FIGS. 146-149, a tissue thickness compensator 52020 cancomprise one or more tubular elements 52080 that laterally traverse thetissue thickness compensator 52020, similar to at least one tissuethickness compensator described herein. In various embodiments, thetissue thickness compensator 52020 can comprise multiple laterallytraversing tubular elements 52080. The tissue thickness compensator52020 can further comprise one or more sheets of material 52024 thathold or retain at least one tubular element 52080 in the tissuethickness compensator 52020. In various embodiments, the one or moresheets of material 52024 can be positioned above and/or below thetubular elements 52080 and can securely retain each tubular element52080 in the tissue thickness compensator 52020. Referring primarily toFIG. 146, the tissue thickness compensator can comprise a first sheet ofmaterial 52024 a and a second sheet of material 52024 b. In variousembodiments, the tubular elements 52080 can be positioned between thefirst and second sheets of material 52024 a, 52024 b. Further, referringstill to FIG. 146, the sheet of material 52024 b can be secured to thetop deck surface 30011 of the rigid support portion of the staplecartridge 30000 such that the tissue thickness compensator 52020 issecurely positioned in the end effector 12. In other embodiments, one ormore of the sheets of material 52024 can be secured to the anvil 30060or otherwise retained in the end effector 12.

In various embodiments, referring primarily to FIG. 147, the tissuethickness compensator 52020 can be porous and/or permeable. For example,the sheet of material 52024 can comprise a plurality of apertures 52026.In various embodiments, the apertures 52026 can be substantiallycircular. In at least one embodiment, the apertures 52036 can be visiblein the sheet of material 52024. In other embodiments, the apertures52036 can be microscopic. Referring still to FIG. 147, the tubularelements 52080 can comprise a plurality of apertures 52026, as well. Invarious embodiments, referring to FIG. 148, a tissue thicknesscompensator 52120 can comprise a sheet of material 52124 that comprisesa plurality of non-circular apertures 52126. For example, the apertures52126 can comprise a diamond and/or slotted shape. In various otherembodiments, referring to FIG. 149, a tissue thickness compensator 52220can comprise a tubular element 52280 that comprises a permeable tubularlattice 52292. In various embodiments, the sheet of material 52224 cancomprise a bioabsorbable, biocompatible elastomeric polymer and cancomprise a medicament, for example.

Similar to at least one embodiment described herein, at least onetubular element 52080 can be configured to swell or expand, asillustrated in FIGS. 150A-150D. For example, referring to FIG. 150A, thetubular elements 52080 can be positioned intermediate the first andsecond sheet of material 52024 a, 52024 b in the tissue thicknesscompensator 52020. When the tissue thickness compensator 52020 contactstissue T, as illustrated in FIG. 150B, the tissue thickness compensator52020 can expand. In various embodiments, for example, the tubularelements 52080 can comprise a hydrophilic substance 52099 that expandswhen exposed to fluid in and/or on the tissue T. Further, the sheet ofmaterial 52024 and tubular elements 52080 can be permeable, as describedherein, such that fluid from the tissue T can permeate the tissuethickness compensator 52020 thereby allowing the fluid to contact thehydrophilic substance 52099 within the tubular elements 52080. As thetubular elements 52080 expand, the sheet of material 52024 surroundingthe tubular elements 52080 can shift or adjust to accommodate theswollen tubular elements 52080. Similar to various tissue thicknesscompensators discussed throughout the present disclosure, the expandedtissue thickness compensator 52020 can be deformed or compressed by anapplied force, such as, for example, a compressive force applied byfired staples, as illustrated in FIG. 150C. Further, the tissuethickness compensator 52020 can be sufficiently resilient such that itproduces a springback force when deformed by the applied force and cansubsequently rebound when the applied force is removed. Referring now toFIGS. 150D and 150E, the tissue thickness compensator 52020 can reboundto different configurations in different staple entrapment areas 30039to appropriately accommodate the captured tissue T.

Referring to FIGS. 151-156, a tissue thickness compensator 53020 cancomprise a plurality of vertically positioned tubular elements 53080. Invarious embodiments, each tubular element 53080 can comprise a tubularaxis that is substantially perpendicular to the top deck surface 30011of the rigid support portion 30010 of the staple cartridge 30000.Further, the first end of each tubular element 53080 can be positionedadjacent to the top deck surface 30011, for example. Similar to at leastone embodiment described herein, the tubular elements 53080 can bedeformable and may comprise an elastomeric polymer, for example. Invarious embodiments, as illustrated in FIG. 152, the tubular elements53080 can be compressed when captured in a staple entrapment area 30039with stapled tissue T. A tubular element 53080 can comprise an elasticmaterial such that deformation of the tubular element 53080 generates arestoring force as the tubular element 53080 seeks to rebound from thedeformed configuration. In some embodiments, deformation of the tubularelement 53080 can be at least partially elastic and at least partiallyplastic. The tubular element 53080 can be configured to act as a springunder an applied force and, in various embodiments, can be configurednot to buckle. In various embodiments, referring to FIG. 153, thetubular elements 53080 can be substantially cylindrical. In someembodiments, referring to FIG. 154, a tubular element 53180 can comprisea buckling region 53112. The tubular element 53180 can be configured tobuckle or deform at the buckling region 53112 when a compressive forceis applied thereto. The tubular element 53180 can deform elasticallyand/or plastically and then be designed to buckle suddenly at thebuckling region 53112 under a preselected buckling force.

Referring primarily to FIG. 155, a first tubular element 53080 can bepositioned at a first end of a staple cavity 30012 and another tubularelement 53080 can be positioned at a second end of the staple cavity30012. As illustrated in FIG. 153, the tubular element 53080 cancomprise a lumen 53084 extending therethrough. Referring again to FIG.152, when the staple 30030 is moved from the initial position to thefired position, each staple leg 30032 can be configured to pass througha lumen 53084 of each tubular element 53080. In various otherembodiments, referring primarily to FIG. 156, vertically positionedtubular elements 54080 can be arranged in a tissue thickness compensator54020 such that the tubular elements 54080 abut or contact each other.In other words, the tubular elements 54080 can be clustered or gatheredtogether. In some embodiments, the tubular elements 54080 can besystematically arranged in the tissue thickness compensator 54020;however, in other embodiments, the tubular elements 54080 can berandomly arranged.

Referring again to FIGS. 151, 155, and 156, the tissue thicknesscompensator 53020 can also comprise a sheet of material 53024 that holdsor retains the tubular elements 53080 in the tissue thicknesscompensator 53020. In various embodiments, the sheet of material 53024can be positioned above and/or below the tubular elements 53080 and cansecurely retain each tubular element 53080 in the tissue thicknesscompensator 53020. In various embodiments, the tissue thicknesscompensator 53020 can comprise a first and a second sheet of material53024. In various embodiments, the tubular elements 53080 can bepositioned between the first and second sheets of material 53024.Further, the sheet of material 53024 can be secured to the top decksurface 30011 of the rigid support portion of the staple cartridge 30000such that the tissue thickness compensator 53020 is securely positionedin the end effector 12. In other embodiments, a sheet of material 53024can be secured to the anvil 30060 or otherwise retained in the endeffector 12. Similar to at least one embodiment described herein, thesheet of material 53024 can be sufficiently deformable such that thesheet of material 53024 deforms as springs 55080 within the tissuethickness compensator are deformed.

Referring to FIGS. 157 and 158, a tissue thickness compensator 55020 cancomprise at least one spring 55080 that is sufficiently resilient suchthat it is capable of producing a springback force when deformed.Referring primarily to FIG. 157, the tissue thickness compensator 55020can comprise a plurality of springs 55080, such as, for example, threerows of springs 55080. The springs 55080 can be systematically and/orrandomly arranged in the tissue thickness compensator 55020. In variousembodiments, the springs 55080 can comprise an elastomeric polymer, forexample. In some embodiments, the shape of the springs 55080 can allowfor deformation thereof. In various embodiments, the springs 55080 canbe deformed from an initial configuration to a deformed configuration.For example, when a portion of the tissue thickness compensator 55020 iscaptured in a staple entrapment area 30039, the springs 55080 in and/oraround the staple entrapment area 30039 can be deformed. In variousembodiments, the springs 55080 can buckle or collapse under acompressive force applied for a fired staple 30030 and the springs 55080may generate a restoring force that is a function of the spring rate ofthe deformed spring 55080 and/or the amount the spring 55080 isdeformed, for example. In some embodiments, the spring 55080 can act asa sponge under a compressive force applied by a fired staple 30030.Further, the spring 55080 can comprise a compensation material, asdescribed in greater detail throughout the present disclosure.

The tissue thickness compensator 55020 can further comprise one or moresheets of material 55024 that hold or retain at least one spring 55080in the tissue thickness compensator 55020. In various embodiments, thesheets of material 55024 can be positioned above and/or below thesprings 55080 and can securely retain the springs 55080 in the tissuethickness compensator 55020. In at least one embodiment, the tissuethickness compensator 55020 can comprise a first sheet of material 55024a and a second sheet of material 55024 b. In various embodiments, thetubular elements 52080 can be positioned between the first and secondsheets of material 55024 a, 55024 b. Referring primarily to FIG. 158, invarious embodiments, the tissue thickness compensator 55020 can furthercomprise a third sheet of material 55024 c positioned adjacent to eitherthe first or second sheet of material 55024 a, 55024 b. In variousembodiments, at least one sheet of material 55024 can be secured to thetop deck surface 30011 of the rigid support portion of the staplecartridge 30000, such that the tissue thickness compensator 55020 issecurely positioned in the end effector 12. In other embodiments, atleast one sheet of material 55024 can be secured to the anvil 30060 orotherwise retained in the end effector 12.

Referring now to FIG. 158, when a staple 30030 is fired from the staplecartridge 30000 (FIG. 156), the staple 30030 can engage the tissuethickness compensator 55020. In various embodiments, the fired staple30030 can capture tissue T and a portion of the tissue thicknesscompensator 55020 in the staple entrapment area 30039. The springs 55080can be deformable such that the tissue thickness compensator 55020compresses when captured by a fired staple 30030. In some embodiments,the springs 55080 can be positioned between fired staples 30030 in thetissue thickness compensator 55020. In other embodiments, at least onespring 55080 can be captured within the staple entrapment area 30039.

Referring to FIG. 159, a tissue thickness compensator 60020 can compriseat least two compensation layers 60022. In various embodiments, thetissue thickness compensator 60020 can comprise a plurality ofcompensation layers 60022 which can be stacked on top of each other,positioned side-by-side, or a combination thereof. As described ingreater detail herein, the compensation layers 60022 of the tissuethickness compensator 60020 can comprise different geometric and/ormaterial properties, for example. Furthermore, as described in greaterdetail herein, pockets and/or channels can exist between adjacentlystacked compensation layers 60022. For example, a tissue thicknesscompensator 62020 can comprise six compensation layers 62022 a, 62022 b,62022 c, 62022 d, 62022 e, 62022 f, which can be adjacently stacked ontop of each other (FIG. 174).

Referring to FIGS. 160, 161, and 163-168, a tissue thickness compensatorcan comprise a first compensation layer 60122 a and a secondcompensation layer 60122 b. In various embodiments, the firstcompensation layer 60122 a can be adjacently stacked on top of thesecond compensation layer 60122 b. In at least one embodiment,adjacently stacked compensation layers 60122 can be separated by aseparation gap or pocket 60132. Referring primarily to FIG. 160, atissue thickness compensator 60120 can also comprise at least onecantilever beam or support 60124 positioned between the first and secondcompensation layers 60122 a, 60122 b. In various embodiments, thesupport 60124 can be configured to position the first compensation layer60122 a relative to the second compensation layer 60122 b such thatcompensation layers 60122 are separated by the separation gap 60132. Asdescribed in greater detail herein, deformation of the support 60124and/or the compensation layers 60122 a, 60122 b, for example, can reducethe separation gap 60132.

The support beam of a tissue thickness compensator can comprise variousgeometries and dimensions. For example, the support beam can be a simpleI-beam, a centered, single-bend support beam 60124 (FIG. 160), anoff-centered, single-bend support beam 60224 (FIG. 161), an ellipticalsupport beam 60324 (FIG. 163), a multi-bend support beam 60424 (FIG.164), and/or a symmetrical, dual-cantilevered support beam 60524 (FIG.165). Furthermore, referring now to FIGS. 160, 166, and 167, a supportbeam 60624 can be thinner than at least one compensation layer 60122(FIG. 166), a support beam 60724 can be thicker than at least onecompensation layer 60122 (FIG. 167), and/or a support beam 60124 can besubstantially the same thickness as at least one compensation layer60122 (FIG. 160), for example. The material, geometry and/or dimensionsof the support beam 60124, for example, can affect the deformability andspringback resiliency of the tissue thickness compensator 60120.

Referring still to FIG. 160, the compensation layers 60122 and supportbeam 60124 of the tissue thickness compensator 60120 can comprisedifferent materials, such as, for example, structural material,biological material, and/or electrical material, for example. Forexample, in various embodiments, at least one compensation layer 60122can comprise a polymeric composition. The polymeric composition cancomprise an at least partially elastic material such that deformation ofthe compensation layer 60122 and/or the support beam 60124 can generatea springback force. The polymeric composition of the compensation layer60122 can comprise non-absorbable polymers, absorbable polymers, orcombinations thereof. In some embodiments, the absorbable polymers caninclude bioabsorbable, biocompatible elastomeric polymers, for example.Furthermore, the polymeric composition of the compensation layer 60122can comprise synthetic polymers, non-synthetic polymers, or combinationsthereof. Examples of synthetic polymers include, but are not limited to,polyglycolic acid (PGA), poly(lactic acid) (PLA), polycaprolactone(PCL), polydioxanone (PDO), and copolymers thereof. Examples ofnon-synthetic polymers include, but are not limited to, polysaccharides,glycoprotein, elastin, proteoglycan, gelatin, collagen, and oxidizedregenerated cellulose (ORC). In various embodiments, similar to thepolymeric compositions in embodiments described herein, the polymericcomposition of the compensation layers 60122 can include varied amountsof absorbable polymers, non-absorbable polymers, synthetic polymers, andnon-synthetic polymers, for example, by weight percentage. In variousembodiments, each compensation layer 60022 in the tissue thicknesscompensator 60120 can comprise a different polymeric composition or, invarious other embodiments, at least two compensation layers 60122 cancomprise the same polymeric composition.

Referring again to FIG. 159, in various embodiments, at least onecompensation layer 60022 can comprise a therapeutic agent 60098 such asa medicament or pharmaceutically active agent, for example. Thecompensation layer 60022 can release a therapeutically effective amountof the therapeutic agent 60098. In various embodiments, the therapeuticagent 60098 can be released as the compensation layer 60022 is absorbed.Examples of therapeutic agents 60098 can include, but are not limitedto, haemostatic agents and drugs, such as, for example, fibrin,thrombin, and/or oxidized regenerated cellulose (ORC), anti-inflammatorydrugs such as, for example, diclofenac, aspirin, naproxen, sulindac,and/or hydrocortisone antibiotic and antimicrobial drugs or agents suchas, for example, triclosan, ionic silver, ampicillin, gentamicin,polymyxin B, and/or chloramphenicol, and/or anticancer agents such as,for example, cisplatin, mitomycin, and/or adriamycin. In someembodiments, the therapeutic agent 60098 can comprise a biologic, suchas a stem cell, for example. In various embodiments, each compensationlayer 60022 in a tissue thickness compensator 60020 can comprise adifferent therapeutic agent 60098 or, in various other embodiments, atleast two compensation layers 60022 can comprise the same therapeuticagent 60098. In at least one embodiment, a compensation layer 60022comprising a therapeutic agent 60098, such as a biologic, for example,can be encased between two structural compensation layers 60022comprising a polymeric composition, such as, for example, polyglycolicacid (PGA) foam, for example. In various embodiments, a compensationlayer 60022 can also comprise an electrically conductive material, suchas, for example, copper.

In various embodiments, referring again to FIG. 174, the compensationlayers 62022 in the tissue thickness compensator 62020 can havedifferent geometries. When layers 62022 are adjacently positioned in thetissue thickness compensator 62020, the compensation layers 62022 canform at least one three-dimensional conduit 62032 between the layers62022. For example, when a second compensation layer 62022 b comprisinga channel is positioned above a substantially flat third compensationlayer 62022 c, the channel and flat surface of the third compensationlayer 62022 c can define a three-dimensional conduit 62032 atherebetween. Similarly, for example, when a fifth compensation layer62022 e comprising a channel is positioned below a fourth compensationlayer 62022 d comprising a corresponding channel, the channels can forma three-dimensional conduit 62032 b defined by the channels in theadjacently stacked compensation layers 62022 d, 62022 e. In variousembodiments, the conduits 62032 can direct therapeutic agents and/orbodily fluids as the fluids flow through the tissue thicknesscompensator 62020.

In various embodiments, referring to FIG. 170, a tissue thicknesscompensator 61020 can comprise compensation layers 61022, such as layers60122 a and 21022 b, configured to receive staples 30030 deployed fromthe staple cartridge 20000 (FIG. 169). As a staple 30030 is moved froman initial position to a fired position, the geometry of at least onecompensation layer 61022 can guide the staple legs 30032 to the firedposition. In various embodiments, at least one compensation layer 61022can comprise apertures 61030 extending therethrough, wherein theapertures 61030 can be arranged to receive the staple legs 30032 ofdeployed staples 30030 when the staples 30030 are fired from the staplecartridge 20000 (FIG. 169), as described in greater detail herein. Invarious other embodiments, referring again to FIG. 174, staple legs30032 can pierce through at least one compensation layer, such ascompensation layer 62022 f, for example, and can be received throughapertures 62030 in at least one compensation layer, such as, forexample, compensation layer 62022 a.

Referring primarily to FIG. 170, the tissue thickness compensator 60120can comprise at least one support tab 61026 on one of the compensationlayers 61022 a, 61022 b. The support tab 61026 can protrude into theseparation gap 61032 defined between adjacent compensation layers, suchas the gap 61032 between the first compensation layer 61020 a and secondcompensation layer 61020 b. In various embodiments, the support tab61026 can protrude from a longitudinal side of a first compensationlayer 61022 a. Further, the support tab 61026 can extend along thelength of the longitudinal side or only along a portion thereof. Invarious embodiments, at least one support tab 61026 can protrude fromtwo longitudinal sides of the compensation layer 61022 a, 61022 b.Further, adjacently positioned compensation layers 61022 a, 61022 b cancomprise corresponding support tabs 60126, such that the support tab60126 that extends from the first compensation layer 60122 a can atleast partially align with the support tab 60126 that extends from thesecond compensation layer 60122 b. In at least one embodiment, referringagain to FIG. 168, a tissue thickness compensator 60820 can comprise alimiter plate 60828 between adjacent compensation layers 60122 a, 60122b. The limiter plate 60828 can be positioned in the gap 60132 definedbetween the first compensation layer 60122 a and the second compensationlayer 60122 b, for example. As described in greater detail herein,support tab(s) 61026 and/or limiter plate(s) 60828 can control thedeformation and/or deflection of a support 60124 and/or the compensationlayers 60122 a, 60122 b.

As described herein, in various embodiments, the compensation layers60022 of the tissue thickness compensator 60020 can comprise differentmaterials, geometries and/or dimensions. Such tissue thicknesscompensators 60020 can be assembled by a variety of manufacturingtechniques. Referring primarily to FIG. 159, the tissue thicknesscompensator 60022 can be manufactured by lithographic,stereolithographic (SLA), or silk screening processes. For example, astereolithographic manufacturing process can create a tissue thicknesscompensator 60020 in which each compensation layer 60022 comprisesdifferent materials and/or geometric features. For example, anultraviolet light in a stereolithography machine can draw the geometryof a first compensation layer 60022, such that the first compensationlayer 60022 comprising a first material, geometry and/or dimensions iscured by the ultraviolet light. The ultraviolet light can subsequentlydraw the geometry of a second compensation layer 60022, such that thesecond compensation layer 60022 comprising a second material, geometryand/or dimensions is cured by the ultraviolet light. In variousembodiments, a stereolithography machine can draw compensation layers60022 on top of each other, side-by-side, or a combination thereof.Further, the compensation layers 60022 can be drawn such that pockets60132 exist between adjacent compensation layers 60022. Because astereolithography machine can create very thin layers having uniquegeometries, a tissue thickness compensator 60020 manufactured by astereolithographic process can comprise a very complex three-dimensionalgeometry.

In various embodiments, referring to FIG. 169, the tissue thicknesscompensator 60920 can be positioned in the end effector 12 of a surgicalinstrument 10 (FIG. 1). The tissue thickness compensator 60920 can bepositioned relative to the staple cartridge 20000 of the end effector12. For example, the tissue thickness compensator 60920 can bereleasably secured to the staple cartridge 20000. In at least oneembodiment, at least one compensation layer 60922 of the tissuethickness compensator 60920 can be positioned adjacent to the top decksurface 20011 (FIG. 79) of the staple cartridge 20000. For example, asecond compensation layer 60922 b can be secured to the top deck surface20011 by an adhesive or by a wrap, similar to at least one of the wrapsdescribed herein (FIG. 16). In various embodiments, the tissue thicknesscompensator 60920 can be integral to the staple cartridge 20000 suchthat the staple cartridge 20000 and the tissue thickness compensator60920 are formed as a single unit construction. For example, the staplecartridge 20000 can comprise a first body portion, such as the rigidsupport portion 20010 (FIG. 79), and a second body portion, such the astissue thickness compensator 60920.

Still referring to FIG. 169, the tissue thickness compensator 60920 cancomprise a first compensator portion 60920 a and a second compensatorportion 60920 b. The first compensator portion 60920 a can be positionedon a first longitudinal side of the staple cartridge 20000 and thesecond compensator portion 60920 b can be positioned on a secondlongitudinal side of the staple cartridge 20000. In various embodiments,when the tissue thickness compensator 60920 is positioned relative tothe staple cartridge 20000, the longitudinal slot 20015 (FIG. 78) in therigid support portion 20010 (FIG. 78) can extend between the firstcompensator portion 60920 a and the second compensator portion 60920 b.When the cutting element 20052 on the staple-firing sled 20050 (FIG. 78)translates through the end effector 12, the cutting element 20052 canpass through the longitudinal slot 20015 between the first compensatorportion 60920 a and the second compensator portion 60920 b withoutsevering a portion of the tissue thickness compensator 60920, forexample. In other embodiments, the cutting element 20052 can beconfigured to sever a portion of the tissue thickness compensator 60920.

In various embodiments, referring now to FIG. 162, a tissue thicknesscompensator 63020 can be configured to fit in the end effector 12′ of acircular surgical instrument. In various embodiments, the tissuethickness compensator 62030 can comprise a circular first compensationlayer 63022 a and a circular second compensation layer 63022 b. Thesecond compensation layer 63022 b can be positioned on a circular topdeck surface 20011′ of a circular staple cartridge 20000′, wherein thesecond compensation layer 63022 b can comprise a geometry thatcorresponds to the geometry of the deck surface 20011′. For example, thedeck surface 20011′ can comprise a stepped portion and the secondcompensation layer 63022 b can comprise a corresponding stepped portion.Similar to various embodiments described herein, the tissue thicknesscompensator can further comprise at least one support 63024 and/orsupport tabs 63026, for example, extending around the tissue thicknesscompensator 63020.

Referring again to FIG. 170, fired staples 30030 can be configured toengage the tissue thickness compensator 60920. As described throughoutthe present disclosure, a fired staple 30030 can capture a portion ofthe tissue thickness compensator 60920 and tissue T and apply acompressive force to the tissue thickness compensator 60920. Further,referring primarily to FIGS. 171-173, the tissue thickness compensator60920 can be deformable. In various embodiments, as described herein, afirst compensation layer 60920 a can be separated from a secondcompensation layer 60920 b by a separation gap 60932. Referring to FIG.171, prior to compression of the tissue thickness compensator 60920, thegap 60932 can comprise a first distance. When a compressive force A isapplied to the tissue thickness compensator 60920 and tissue T, forexample, by a fired staple 30030 (FIG. 170), the support 60924 can beconfigured to deform. Referring now to FIG. 172, the single-bend supportbeam 60924 can bend under the compressive force A such that theseparation gap 60932 between the first compensation layer 60920 a andthe second compensation layer 60920 b is reduced to a second distance.Referring primarily to FIG. 173, the first and second compensationlayers 60922 a, 60922 b can also deform under the compressive force A.In various embodiments, the support tabs 60926 can control deformationof the compensation layers 60920. For example, the support tabs 60926can prevent excessive bending of the compensation layers 60920 bysupporting the longitudinal sides of the compensation layer 60920 whenthey come into contact with one another. The support tabs 60926 can alsobe configured to bend or bow under the compressive force A. Additionallyor alternatively, the limiter plate 60128 (FIG. 168) described ingreater detail herein, can limit the deformation of the compensationlayers 60920 when the compensation layers 60920 and/or support tabs60926 contact the limiter plate 60128.

Furthermore, similar to various tissue thickness compensators describedherein, tissue thickness compensator 60920 can generate a springback orrestoring force when deformed. The restoring force generated by thedeformed tissue thickness compensator can at least depend on theorientation, dimensions, material, and/or geometry of the tissuethickness compensator 60920, as well as the amount of the tissuethickness compensator 60920 that is deformed by the applied force.Furthermore, in various embodiments, at least a portion of the tissuethickness compensator 60920 can be resilient such that the tissuethickness compensator 60920 generates a spring load or restoring forcewhen deformed by a fired staple 30030. In at least one embodiment, thesupport 60924 can comprise an elastic material and/or at least onecompensation layer 60922 can comprise an elastic material such that thetissue thickness compensator 60920 is resilient.

In various embodiments, referring now to FIG. 175, an end effector of asurgical stapling instrument can comprise a first jaw and a second jaw,wherein at least one of the first jaw and the second jaw can beconfigured to be moved relative to the other. In certain embodiments,the end effector can comprise a first jaw including a staple cartridgechannel 19070 and a second jaw including an anvil 19060, wherein theanvil 19060 can be pivoted toward and/or away from the staple cartridgechannel 19070, for example. The staple cartridge channel 19070 can beconfigured to receive a staple cartridge 19000, for example, which, inat least one embodiment, can be removably retained within the staplecartridge channel 19070. In various embodiments, the staple cartridge19000 can comprise a cartridge body 19010 and a tissue thicknesscompensator 19020 wherein, in at least one embodiment, the tissuethickness compensator 19020 can be removably attached to the cartridgebody 19010. Similar to other embodiments described herein, referring nowto FIG. 176, the cartridge body 19010 can comprise a plurality of staplecavities 19012 and a staple 19030 positioned within each staple cavity19012. Also similar to other embodiments described herein, the staples19030 can be supported by staple drivers 19040 positioned within thecartridge body 19010 wherein a sled and/or firing member, for example,can be advanced through the staple cartridge 19000 to lift the stapledrivers 19040 upwardly within the staple cavities 19012, as illustratedin FIG. 177, and eject the staples 19030 from the staple cavities 19012.

In various embodiments, referring primarily to FIGS. 175 and 176, thetissue thickness compensator 19020 can comprise resilient members 19022and a vessel 19024 encapsulating the resilient members 19022. In atleast one embodiment, the vessel 19024 can be sealed and can define acavity containing an inner atmosphere having a pressure which isdifferent than the surrounding atmospheric pressure. In certainembodiments, the pressure of the inner atmosphere can be greater thanthe pressure of the surrounding atmosphere while, in other embodiments,the pressure of the inner atmosphere can be less than the pressure ofthe surrounding atmosphere. In the embodiments in which the vessel 19024contains a pressure less than the pressure of the surroundingatmosphere, the sidewall of the vessel 19024 can enclose a vacuum. Insuch embodiments, the vacuum can cause the vessel 19024 to distort,collapse, and/or flatten wherein the resilient members 19022 positionedwithin the vessel 19024 can be resiliently compressed within the vessel19024. When a vacuum is drawn on the vessel 19024, the resilient members19022 can deflect or deform downwardly and can be held in position bythe sidewalls of the vessel 19024 in a compressed, or vacuum-packed,state.

Resilient member 19022 and vessel 19024 are comprised of biocompatiblematerials. In various embodiments, resilient member 19022 and/or vessel19024 can be comprised of bioabsorbable materials such as PLLA, PGA,and/or PCL, for example. In certain embodiments, resilient member 19022can be comprised of a resilient material. Resilient member 19022 canalso comprise structural resilience. For example, resilient member 19022can be in the form of a hollow tube.

Further to the above, the tissue thickness compensator 19020 can bepositioned against or adjacent to the deck surface 19011 of thecartridge body 19010. When the staples 19030 are at least partiallyfired, referring now to FIG. 177, the legs of the staples 19030 canpuncture or rupture the vessel 19024. In certain embodiments, the vessel19024 can comprise a central portion 19026 which can be positioned overa cutting slot 19016 of the cartridge body 19010 such that, when acutting member 19080 is advanced to incise tissue T positioned betweenthe staple cartridge 19000 and the anvil 19060, the cutting member 19080can also incise the central portion 19026 of the vessel 19024 therebypuncturing or rupturing the vessel 19024. In either event, once thevessel 19024 has been ruptured, the inner atmosphere within the vessel19024 can equalize with the atmosphere surrounding the tissue thicknesscompensator 19020 and allow the resilient members 19022 to resilientlyexpand to regain, or at least partially regain, their undistorted and/orunflattened configuration. In such circumstances, the resilient members19022 can apply a biasing force to the tissue T captured within thedeformed staples 19020. More specifically, after being deformed by theforming surfaces of pockets 19062 defined in the anvil 19060, the legsof the staples 19030 can capture tissue T and at least a portion of aresilient member 19022 within the staples 19030 such that, when thevessel 19024 ruptures, the tissue thickness compensator 19020 cancompensate for the thickness of the tissue T captured within the staples19030. For instance, when the tissue T captured within a staple 19030 isthinner, a resilient member 19022 captured within that staple 19030 canexpand to fill gaps within the staple 19030 and apply a sufficientcompression force to the tissue T. Correspondingly, when the tissue Tcaptured within a staple 19030 is thicker, a resilient member 19022captured within that staple 19030 can remain compressed to make room forthe thicker tissue within the staple 19030 and, likewise, apply asufficient compression force to the tissue T.

When the vessel 19024 is punctured, as outlined above, the resilientmembers 19022 can expand in an attempt to resiliently return to theiroriginal configuration. In certain circumstances, the portion ofresilient members 19022 that have been captured within the staples 19030may not be able to return to their original undistorted shape. In suchcircumstances, the resilient members 19022 can comprise a spring whichcan apply a compression force to the tissue T captured within thestaples 19030. In various embodiments, a resilient member 19022 canemulate a linear spring wherein the compression force applied by theresilient member 19022 is linearly proportional to the amount, ordistance, in which the resilient member 19022 remains deflected withinthe staple 19030. In certain other embodiments, a resilient member 19022can emulate a non-linear spring wherein the compression force applied bythe resilient member 19022 is not linearly proportional to the amount,or distance, in which the resilient member 19022 remains deflectedwithin the staple 19030.

In various embodiments, referring primarily to FIGS. 178 and 179, astaple cartridge 19200 can comprise a tissue thickness compensator 19220which can comprise one or more sealed vessels 19222 therein. In at leastone embodiment, each of the vessels 19222 can be sealed and can containan inner atmosphere. In certain embodiments, the pressure of the inneratmosphere within a sealed vessel 19222 can exceed atmospheric pressurewhile, in certain other embodiments, the pressure of the inneratmosphere within a sealed vessel 19222 can be below atmosphericpressure. In embodiments where the pressure of the inner atmospherewithin a vessel 19222 is below atmospheric pressure, the vessel 19222can be described as containing a vacuum. In various embodiments, one ormore of the vessels 19222 can be wrapped or contained in an outershroud, container, wrap, and/or film 19224, for example, wherein thetissue thickness compensator 19220 can be positioned above a decksurface 19011 of the cartridge body 19010. In certain embodiments, eachvessel 19222 can be manufactured from a tube having a circular, or an atleast substantially circular, cross-section, for example, having aclosed end and an open end. A vacuum can be drawn on the open end of thetube and, when a sufficient vacuum has been reached within the tube, theopen end can be closed and sealed. In at least one such embodiment, thetube can be comprised of a polymeric material, for example, wherein theopen end of the tube can be heat staked in order to close and seal thesame. In any event, the vacuum within each vessel 19222 can pull thesidewalls of the tube inwardly and resiliently distort and/or flattenthe tube. The vessels 19222 are illustrated in an at least partiallyflattened state in FIG. 179.

When the staples 19030 are in their unfired position, as illustrated inFIG. 179, the tips of the staples 19030 can be positioned below thetissue thickness compensator 19220. In at least one such embodiment, thestaples 19030 can be positioned within their respective staple cavities19012 such that the staples 19030 do not contact the vessels 19222 untilthe staples 19030 are moved from the unfired positions, illustrated inFIG. 179, to their fired positions, illustrated in FIG. 180. In certainembodiments, the wrap 19224 of the tissue thickness compensator 19220can protect the vessels 19220 from being prematurely punctured by thestaples 19030. When the staples 19030 are at least partially fired,referring now to FIG. 180, the legs of the staples 19030 can puncture orrupture the vessels 19222. In such circumstances, the inner atmosphereswithin the vessels 19222 can equalize with the atmosphere surroundingthe vessels 19222 and resiliently expand to regain, or at leastpartially regain, their undistorted and/or unflattened configuration. Insuch circumstances, the punctured vessels 19222 can apply a biasingforce to the tissue captured within the deformed staples 19030. Morespecifically, after being deformed by the forming surfaces of pockets19062 defined in the anvil 19060, the legs of the staples 19030 cancapture tissue T and at least a portion of a vessel 19222 within thestaples 19030 such that, when the vessels 19222 rupture, the vessels19222 can compensate for the thickness of the tissue T captured withinthe staples 19030. For instance, when the tissue T captured within astaple 19030 is thinner, a vessel 19222 captured within that staple19030 can expand to fill gaps within the staple 19030 and, concurrently,apply a sufficient compression force to the tissue T. Correspondingly,when the tissue T captured within a staple 19030 is thicker, a vessel19222 captured within that staple 19030 can remain compressed to makeroom for the thicker tissue within the staple 19030 and, concurrently,apply a sufficient compression force to the tissue T.

When the vessels 19222 are punctured, as outlined above, the vessels19222 can expand in an attempt to resiliently return to their originalconfiguration. The portion of vessels 19222 that have captured withinthe staples 19030 may not be able to return to their originalundistorted shape. In such circumstances, the vessel 19222 can comprisea spring which can apply a compression force to the tissue T capturedwithin the staples 19030. In various embodiments, a vessel 19222 canemulate a linear spring wherein the compression force applied by thevessel 19222 is linearly proportional to the amount, or distance, inwhich the vessel 19222 remains deflected within the staple 19030. Incertain other embodiments, a vessel 19222 can emulate a non-linearspring wherein the compression force applied by the vessel 19222 is notlinearly proportional to the amount, or distance, in which the vessel19222 remains deflected within the staple 19030. In various embodiments,the vessels 19222 can be hollow and, in at least one embodiment, emptywhen they are in their sealed configuration. In certain otherembodiments, each of the vessels 19222 can define a cavity and canfurther include at least one medicament contained therein. In at leastsome embodiments, the vessels 19222 can be comprised of at least onemedicament which can be released and/or bioabsorbed, for example.

In various embodiments, the vessels 19222 of the tissue thicknesscompensator 19220 can be arranged in any suitable manner. As illustratedin FIG. 178, the staple cavities 19012 defined in the cartridge body19010, and the staples 19030 positioned in the staple cavities 19012,can be arranged in rows. In at least the illustrated embodiment, thestaple cavities 19012 can be arranged in six longitudinal, linear rows,for example; however, any suitable arrangement of staple cavities 19012could be utilized. As also illustrated in FIG. 178, the tissue thicknesscompensator 19220 can comprise six vessels 19222 wherein each of thevessels 19222 can be aligned with, or positioned over, a row of staplecavities 19012. In at least one embodiment, each of the staples 19030within a row of staple cavities 19012 can be configured to puncture thesame vessel 19222. In certain situations, some of the staple legs of thestaples 19030 may not puncture the vessel 19222 positioned thereover;however, in embodiments where the vessel 19222 defines a continuousinternal cavity, for example, the cavity can be sufficiently puncturedby at least one of the staples 19030 in order to allow the pressure ofthe internal cavity atmosphere to equalize with the atmospheric pressuresurrounding the vessel 19222. In various embodiments, referring now toFIG. 185, a tissue thickness compensator can comprise a vessel, such asvessel 19222′, for example, which can extend in a direction which istransverse to a line of staples 19030. In at least one such embodiment,a vessel 19222′ can extend across multiple staple rows. In certainembodiments, referring now to FIG. 186, a tissue thickness compensator19220″ can comprise a plurality of vessels 19222″ which extend in adirection which is perpendicular, or at least substantiallyperpendicular, to a line of staples 19030. In at least one suchembodiment, some of the vessels 19222″ may be punctured by the staples19030 while others may not be punctured by the staples 19030. In atleast one embodiment, the vessels 19222″ can extend across or through acutting path in which a cutting member could transect and rupture thevessels 19222″, for example.

In various embodiments, as described above, a tissue thicknesscompensator, such as tissue thickness compensator 19220, for example,can comprise a plurality of sealed vessels, such as vessels 19222, forexample. As also described above, each of the sealed vessels 19222 cancomprise a separate internal atmosphere. In certain embodiments, thevessels 19222 can have different internal pressures. In at least oneembodiment, for example, a first vessel 19222 can comprise an internalvacuum having a first pressure and a second vessel 19222 can comprise aninternal vacuum having a second, different pressure, for example. In atleast one such embodiment, the amount of distortion or flattening of avessel 19222 can be a function of the vacuum pressure of the internalatmosphere contained therein. For instance, a vessel 19222 having agreater vacuum can be distorted or flattened a greater amount ascompared to a vessel 19222 having a smaller vacuum. In certainembodiments, the cavity of a vessel can be segmented into two or moreseparate, sealed cavities wherein each separate, sealed cavity cancomprise a separate internal atmosphere. In at least one suchembodiment, some of the staples within a staple row can be configuredand arranged to puncture a first cavity defined in the vessel whileother staples within the staple row can be configured and arranged topuncture a second cavity defined in the vessel, for example. In suchembodiments, especially in embodiments in which the staples in a staplerow are sequentially fired from one end of the staple row to the other,as described above, one of the cavities can remain intact and canmaintain its internal atmosphere when another cavity is ruptured. Incertain embodiments, the first cavity can have an inner atmospherehaving a first vacuum pressure and the second cavity can have an inneratmosphere having a second, different vacuum pressure, for example. Invarious embodiments, a cavity that remains intact can maintain its innerpressure until the vessel is bioabsorbed thereby creating a timedpressure release.

In various embodiments, referring now to FIGS. 181 and 182, a tissuethickness compensator, such as tissue thickness compensator 19120, forexample, can be attached to an anvil 19160. Similar to the above, thetissue thickness compensator 19120 can comprise a vessel 19124 and aplurality of resilient members 19122 positioned therein. Also similar tothe above, the vessel 19124 can define a cavity containing an inneratmosphere having a pressure which is less than or greater than thepressure of the atmosphere surrounding the tissue thickness compensator19120. In embodiments where the inner atmosphere within the vessel 19124comprises a vacuum, the vessel 19124 and the resilient members 19122positioned therein can be distorted, collapsed, and/or flattened by thedifference in pressure between the vacuum in the vessel 19124 and theatmospheric pressure outside of the vessel 19124. In use, the anvil19160 can be moved into a closed position in which it is positionedopposite a staple cartridge 19100 and in which a tissue engaging surface19121 on the vessel 19124 can engage the tissue T positionedintermediate the tissue thickness compensator 19120 and a staplecartridge 19100. In use, the firing member 19080 can be advanceddistally to fire the staples 19030, as described above, and, at the sametime, incise the tissue T. In at least one embodiment, the tissuethickness compensator 19120 can further comprise an intermediate portion19126 which can be aligned with a cutting slot defined in the anvil19160 wherein, when the firing member 19080 is advanced distally throughthe tissue thickness compensator 19120, the firing member 19080 canpuncture or rupture the vessel 19124. Also, similar to the above, thefiring member 19080 can lift the staple drivers 19040 upwardly and firethe staples 19030 such that the staples 19030 can contact the anvil19160 and be deformed into their deformed configuration, as illustratedin FIG. 183. When the staples 19030 are fired, the staples 19030 canpierce the tissue T and then pierce or rupture the vessel 19124 suchthat the resilient members 19122 positioned within the vessel 19124 canat least partially expand, as outlined above.

In various embodiments, further to the above, a tissue thicknesscompensator can be comprised of a biocompatible material. Thebiocompatible material, such as, a foam, may comprise tackifiers,surfactants, fillers, cross-linkers, pigments, dyes, antioxidants andother stabilizers and/or combinations thereof to provide desiredproperties to the material. In certain embodiments, a biocompatible foammay comprise a surfactant. The surfactant may be applied to the surfaceof the material and/or dispersed within the material. Without wishing tobe bound to any particular theory, the surfactant applied to thebiocompatible material may reduce the surface tension of the fluidscontacting the material. For example, the surfactant may reduce thesurface tension of water contacting the material to accelerate thepenetration of water into the material. In various embodiments, thewater may act as a catalyst. The surfactant may increase thehydrophilicity of the material.

In various embodiments, the surfactant may comprise an anionicsurfactant, a cationic surfactant, and/or a non-ionic surfactant.Examples surfactants include, but are not limited to polyacrylic acid,methalose, methyl cellulose, ethyl cellulose, propyl cellulose, hydroxyethyl cellulose, carboxy methyl cellulose, polyoxyethylene cetyl ether,polyoxyethylene lauryl ether, polyoxyethylene octyl ether,polyoxyethylene octylphenyl ether, polyoxyethylene oleyl ether,polyoxyethylene sorbitan monolaurate, polyoxyethylene stearyl ether,polyoxyethylene nonylphenyl ether, dialkylphenoxypoly(ethyleneoxy)ethanol, and polyoxamers, and combinations thereof. Inat least one embodiment, the surfactant may comprise a copolymer ofpolyethylene glycol and polypropylene glycol. In at least oneembodiment, the surfactant may comprise a phospholipid surfactant. Thephospholipid surfactant may provide antibacterial stabilizing propertiesand/or disperse other materials in the biocompatible material. Invarious embodiments, the tissue thickness compensator may comprise atleast one medicament. The tissue thickness compensator may comprise oneor more of the natural materials, non-synthetic materials, and/orsynthetic materials described herein. In certain embodiments, the tissuethickness compensator may comprise a biocompatible foam comprisinggelatin, collagen, hyaluronic acid, oxidized regenerated cellulose,polyglycolic acid, polycaprolactone, polylactic acid, polydioxanone,polyhydroxyalkanoate, poliglecaprone, and combinations thereof. Incertain embodiments, the tissue thickness compensator may comprise afilm comprising the at least one medicament. In certain embodiments, thetissue thickness compensator may comprise a biodegradable filmcomprising the at least one medicament. In certain embodiments, themedicament may comprise a liquid, gel, and/or powder. In variousembodiments, the medicaments may comprise anticancer agents, such as,for example, cisplatin, mitomycin, and/or adriamycin.

In various embodiments, the tissue thickness compensator may comprise abiodegradable material to provide controlled elution of the at least onemedicament as the biodegradable material degrades. In variousembodiments, the biodegradable material may degrade may decompose, orloses structural integrity, when the biodegradable material contacts anactivator, such as, for example an activator fluid. In variousembodiments, the activator fluid may comprise saline or any otherelectrolyte solution, for example. The biodegradable material maycontact the activator fluid by conventional techniques, including, butnot limited to spraying, dipping, and/or brushing. In use, for example,a surgeon may dip an end effector and/or a staple cartridge comprisingthe tissue thickness compensator comprising the at least one medicamentinto an activator fluid comprising a salt solution, such as sodiumchloride, calcium chloride, and/or potassium chloride. The tissuethickness compensator may release the medicament as the tissue thicknesscompensator degrades. In certain embodiments, the elution of themedicament from the tissue thickness compensator may be characterized bya rapid initial elution rate and a slower sustained elution rate.

In various embodiments, a tissue thickness compensator, for example, canbe comprised of a biocompatible material which may comprise an oxidizingagent. In various embodiments, the oxidizing agent may an organicperoxide and/or an inorganic peroxide. Examples of oxidizing agents mayinclude, but are not limited to, hydrogen peroxide, urea peroxide,calcium peroxide, and magnesium peroxide, and sodium percarbonate. Invarious embodiments, the oxidizing agent may comprise peroxygen-basedoxidizing agents and hypohalite-based oxidizing agents, such as, forexample, hydrogen peroxide, hypochlorous acid, hypochlorites,hypocodites, and percarbonates. In various embodiments, the oxidizingagent may comprise alkali metal chlorites, hypochlorites and perborates,such as, for example, sodium chlorite, sodium hypochlorite and sodiumperborate. In certain embodiments, the oxidizing agent may comprisevanadate. In certain embodiments, the oxidizing agent may compriseascorbic acid. In certain embodiments, the oxidizing agent may comprisean active oxygen generator. In various embodiments, a tissue scaffoldmay comprise the biocompatible material comprising an oxidizing agent.

In various embodiments, the biocompatible material may comprise aliquid, gel, and/or powder. In certain embodiments, the oxidizing agentmay comprise microparticles and/or nanoparticles, for example. Forexample, the oxidizing agent may be milled into microparticles and/ornanoparticles. In certain embodiments, the oxidizing agent may beincorporated into the biocompatible material by suspending the oxidizingagent in a polymer solution. In certain embodiments, the oxidizing agentmay be incorporated into the biocompatible material during thelyophylization process. After lyophylization, the oxidizing agent may beattached to the cell walls of the biocompatible material to interactwith the tissue upon contact. In various embodiments, the oxidizingagent may not be chemically bonded to the biocompatible material. In atleast one embodiment, a percarbonate dry power may be embedded within abiocompatible foam to provide a prolonged biological effect by the slowrelease of oxygen. In at least one embodiment, a percarbonate dry powermay be embedded within a polymeric fiber in a non-woven structure toprovide a prolonged biological effect by the slow release of oxygen. Invarious embodiments, the biocompatible material may comprise anoxidizing agent and a medicament, such as, for example, doxycycline andascorbic acid.

In various embodiments, the biocompatible material may comprise a rapidrelease oxidizing agent and/or a slower sustained release oxidizingagent. In certain embodiments, the elution of the oxidizing agent fromthe biocompatible material may be characterized by a rapid initialelution rate and a slower sustained elution rate. In variousembodiments, the oxidizing agent may generate oxygen when the oxidizingagent contacts bodily fluid, such as, for example, water. Examples ofbodily fluids may include, but are not limited to, blood, plasma,peritoneal fluid, cerebral spinal fluid, urine, lymph fluid, synovialfluid, vitreous fluid, saliva, gastrointestinal luminal contents, and/orbile. Without wishing to be bound to any particular theory, theoxidizing agent may reduce cell death, enhance tissue viability and/ormaintain the mechanical strength of the tissue to tissue that may bedamaged during cutting and/or stapling. In various embodiments, thebiocompatible material may comprise at least one microparticle and/ornanoparticle. The biocompatible material may comprise one or more of thenatural materials, non-synthetic materials, and synthetic materialsdescribed herein. In various embodiments, the biocompatible material maycomprise particles having a mean diameter of about 10 nm to about 100 nmand/or about 10 μm to about 100 μm, such as, for example, 45-50 nmand/or 45-50 μm. In various embodiments, the biocompatible material maycomprise biocompatible foam comprising at least one microparticle and/ornanoparticle embedded therein. The microparticle and/or nanoparticle maynot be chemically bonded to the biocompatible material. Themicroparticle and/or nanoparticle may provide controlled release of themedicament. In certain embodiments, the microparticle and/ornanoparticle may comprise at least one medicament. In certainembodiments, the microparticle and/or nanoparticle may comprise ahemostatic agent, an anti-microbial agent, and/or an oxidizing agent,for example. In certain embodiments, the tissue thickness compensatormay comprise a biocompatible foam comprising an hemostatic agentcomprising oxidized regenerated cellulose, an anti-microbial agentcomprising doxycline and/or Gentamicin, and/or an oxidizing agentcomprising a percarbant. In various embodiments, the microparticleand/or nanoparticle may provide controlled release of the medicament upto three days, for example.

In various embodiments, the microparticle and/or nanoparticle may beembedded in the biocompatible material during a manufacturing process.For example, a biocompatible polymer, such as, for example, a PGA/PCL,may contact a solvent, such as, for example, dioxane to form a mixture.The biocompatible polymer may be ground to form particles. Dryparticles, with or without ORC particles, may be contacted with themixture to form a suspension. The suspension may be lyophilized to forma biocompatible foam comprising PGA/PCL having dry particles and/or ORCparticles embedded therein.

In various embodiments, the tissue thickness compensators or layersdisclosed herein can be comprised of an absorbable polymer, for example.In certain embodiments, a tissue thickness compensator can be comprisedof foam, film, fibrous woven, fibrous non-woven PGA, PGA/PCL(Poly(glycolic acid-co-caprolactone)), PLA/PCL (Poly(lacticacid-co-polycaprolactone)), PLLA/PCL, PGA/TMC (Poly(glycolicacid-co-trimethylene carbonate)), PDS, PEPBO or other absorbablepolyurethane, polyester, polycarbonate, Polyorthoesters, Polyanhydrides,Polyesteramides, and/or Polyoxaesters, for example. In variousembodiments, a tissue thickness compensator can be comprised of PGA/PLA(Poly(glycolic acid-co-lactic acid)) and/or PDS/PLA(Poly(p-dioxanone-co-lactic acid)), for example. In various embodiments,a tissue thickness compensator can be comprised of an organic material,for example. In certain embodiments, a tissue thickness compensator canbe comprised of Carboxymethyl Cellulose, Sodium Alginate, Cross-linkedHyaluronic Acid, and/or Oxidized regenerated cellulose, for example. Invarious embodiments, a tissue thickness compensator can comprise adurometer in the 3-7 Shore A (30-50 Shore OO) ranges with a maximumstiffness of 15 Shore A (65 Shore OO), for example. In certainembodiments, a tissue thickness compensator can undergo 40% compressionunder 3 lbf load, 60% compression under 6 lbf load, and/or 80%compression under 20 lbf load, for example. In certain embodiments, oneor more gasses, such as air, nitrogen, carbon dioxide, and/or oxygen,for example, can be bubbled through and/or contained within the tissuethickness compensator. In at least one embodiment, a tissue thicknesscompensator can comprise beads therein which comprise betweenapproximately 50% and approximately 75% of the material stiffnesscomprising the tissue thickness compensator.

In various embodiments, a tissue thickness compensator can comprisehyaluronic acid, nutrients, fibrin, thrombin, platelet rich plasma,Sulfasalazine (Azulfidine®—5ASA+Sulfapyridine diazobond))—prodrug—colonic bacterial (Azoreductase), Mesalamine (5ASA withdifferent prodrug configurations for delayed release), Asacol®(5ASA+Eudragit-S coated—pH>7 (coating dissolution)), Pentasa®(5ASA+ethylcellulose coated—time/pH dependent slow release), Mesasal®(5ASA+Eudragit-L coated—pH>6), Olsalazine (5ASA+5ASA—colonic bacterial(Azoreductase)), Balsalazide (5ASA+4-Aminobenzoyl-B-alanine)—colonicbacterial (Azoreductase)), Granulated mesalamine, Lialda (delay and SRformulation of mesalamine), HMPL-004 (herbal mixture that may inhibitTNF-alpha, interleukin-1 beta, and nuclear-kappa B activation), CCX282-B(oral chemokine receptor antagonist that interferes with trafficking ofT lymphocytes into the intestinal mucosa), Rifaximin (nonabsorbablebroad-spectrum antibiotic), Infliximab, murine chymieric (monoclonalantibody directed against TNF-alpha-approved for reducing signs/symptomsand maintaining clinical remission in adult/pediatric patients withmoderate/severe luminal and fistulizing Crohn's disease who have hadinadequate response to conventional therapy), Adalimumab, Total HumanIgG1 (anti-TNF-alpha monoclonal antibody—approved for reducingsigns/symptoms of Crohn's disease, and for the induction and maintenanceof clinical remission in adult patients with moderate/severe activeCrohn's disease with inadequate response to conventional therapies, orwho become intolerant to Infliximab), Certolizumab pegoll, humanizedanti-TNF FAB' (monoclonal antibody fragment linked to polyethyleneglycol—approved for reducing signs/symptoms of Crohn's disease and forthe induction and maintenance of response in adult patients w/moderate/severe disease with inadequate response to conventionaltherapies), Natalizumab, First non-TNF-alpha inhibitor (biologiccompound approved for Crohn's disease), Humanized monoclonal IgG4antibody (directed against alpha-4 integrin—FDA approved for inducingand maintaining clinical response and remission in patients withmoderate/severe disease with evidence of inflammation and who have hadinadequate response to or are unable to tolerate conventional Crohn'stherapies and inhibitors of TNF-alpha), concomitant Immunomodulatorspotentially given with Infliximab, Azathioprine 6-Mercaptopurine (purinesynthesis inhibitor—prodrug), Methotrexate (binds dihydrofolatereductase (DHFR) enzyme that participates in tetrahydrofolate synthesis,inhibits all purine synthesis), Allopurinol and Thioprine therapy, PP1,H2 for acid suppression to protect the healing line, C-Diff—Flagyl,Vancomycin (fecal translocation treatment; probiotics; repopulation ofnormal endoluminal flora), and/or Rifaximin (treatment of bacterialovergrowth (notably hepatic encephalopathy); not absorbed in GI tractwith action on intraluminal bacteria), for example.

As described herein, a tissue thickness compensator can compensate forvariations in the thickness of tissue that is captured within thestaples ejected from a staple cartridge and/or contained within a stapleline, for example. Stated another way, certain staples within a stapleline can capture thick portions of the tissue while other staples withinthe staple line can capture thin portions of the tissue. In suchcircumstances, the tissue thickness compensator can assume differentheights or thicknesses within the staples and apply a compressive forceto the tissue captured within the staples regardless of whether thecaptured tissue is thick or thin. In various embodiments, a tissuethickness compensator can compensate for variations in the hardness ofthe tissue. For instance, certain staples within a staple line cancapture highly compressible portions of the tissue while other stapleswithin the staple line can capture portions of the tissue which are lesscompressible. In such circumstances, the tissue thickness compensatorcan be configured to assume a smaller height within the staples thathave captured tissue having a lower compressibility, or higher hardness,and, correspondingly, a larger height within the staples that havecaptured tissue having a higher compressibility, or lower hardness, forexample. In any event, a tissue thickness compensator, regardless ofwhether it compensates for variations in tissue thickness and/orvariations in tissue hardness, for example, can be referred to as a‘tissue compensator’ and/or as a ‘compensator’, for example.

The devices disclosed herein can be designed to be disposed of after asingle use, or they can be designed to be used multiple times. In eithercase, however, the device can be reconditioned for reuse after at leastone use. Reconditioning can include any combination of the steps ofdisassembly of the device, followed by cleaning or replacement ofparticular pieces, and subsequent reassembly. In particular, the devicecan be disassembled, and any number of the particular pieces or parts ofthe device can be selectively replaced or removed in any combination.Upon cleaning and/or replacement of particular parts, the device can bereassembled for subsequent use either at a reconditioning facility, orby a surgical team immediately prior to a surgical procedure. Thoseskilled in the art will appreciate that reconditioning of a device canutilize a variety of techniques for disassembly, cleaning/replacement,and reassembly. Use of such techniques, and the resulting reconditioneddevice, are all within the scope of the present application.

Preferably, the invention described herein will be processed beforesurgery. First, a new or used instrument is obtained and if necessarycleaned. The instrument can then be sterilized. In one sterilizationtechnique, the instrument is placed in a closed and sealed container,such as a plastic or TYVEK bag. The container and instrument are thenplaced in a field of radiation that can penetrate the container, such asgamma radiation, x-rays, or high-energy electrons. The radiation killsbacteria on the instrument and in the container. The sterilizedinstrument can then be stored in the sterile container. The sealedcontainer keeps the instrument sterile until it is opened in the medicalfacility.

Any patent, publication, or other disclosure material, in whole or inpart, that is said to be incorporated by reference herein isincorporated herein only to the extent that the incorporated materialsdoes not conflict with existing definitions, statements, or otherdisclosure material set forth in this disclosure. As such, and to theextent necessary, the disclosure as explicitly set forth hereinsupersedes any conflicting material incorporated herein by reference.Any material, or portion thereof, that is said to be incorporated byreference herein, but which conflicts with existing definitions,statements, or other disclosure material set forth herein will only beincorporated to the extent that no conflict arises between thatincorporated material and the existing disclosure material.

While this invention has been described as having exemplary designs, thepresent invention may be further modified within the spirit and scope ofthe disclosure. This application is therefore intended to cover anyvariations, uses, or adaptations of the invention using its generalprinciples. Further, this application is intended to cover suchdepartures from the present disclosure as come within known or customarypractice in the art to which this invention pertains.

What is claimed is:
 1. A tissue thickness compensator comprising a tubular element, wherein the tubular element comprises: a first layer comprising a first biocompatible material sealingly enclosed in a water impermeable material; and a second layer comprising a second biocompatible material comprising at least one encapsulation; wherein the first biocompatible material comprises a temperature activatable precursor, wherein the temperature activatable precursor is activatable between an inactive state and an active state, and wherein the first biocompatible material expands when contacted with a fluid.
 2. The tissue thickness compensator of claim 1 comprising a third layer comprising a third biocompatible material.
 3. The tissue thickness compensator of claim 2, wherein each of the first layer and second layer comprise a tissue-contacting surface.
 4. The tissue thickness compensator of claim 2, wherein the first biocompatible material, second biocompatible material, and third biocompatible material are independently selected from albumin, alginate, carbohydrate, casein, cellulose, chitin, chitosan, collagen, blood, dextran, elastin, fibrin, fibrinogen, gelatin, heparin, hyaluronic acid, keratin, protein, serum, starch, poly(lactic acid), poly(glycolic acid), poly(hydroxybutyrate), poly(phosphazine), polyesters, polyethylene glycols, polyalkyleneoxides, polyacrylam ides, polycarbonates, polyhydroxyethylmethylacrylate, poly(vinylpyrrolidone), polyvinyl alcohols, poly(caprolactone), poly(dioxanone), polyacrylic acid, polyacetate, polypropylene, glycerols, poly(amino acids), copoly(ether-esters), polyalkylene oxalates, polyamides, poly(iminocarbonates), polyoxaesters, polyorthoesters, polyphosphazenes and combinations thereof.
 5. The tissue thickness compensator of claim 1, wherein the first biocompatible material comprises a dry hydrogel.
 6. The tissue thickness compensator of claim 5, wherein the hydrogel comprises polyalkylene oxides, polysaccharides, esters, aliphatic esters, orthoesters, phosphoesters, carbonates, urethanes, ethers, amides, phenolics, and combinations thereof.
 7. The tissue thickness compensator of claim 1, wherein the first biocompatible material is a water-swellable composition.
 8. The tissue thickness compensator of claim 1, wherein the fluid comprises water, saline, and a bodily fluid.
 9. The tissue thickness compensator of claim 1, wherein the first biocompatible material contacts the fluid when the water impermeable material is ruptured.
 10. The tissue thickness compensator of claim 1, wherein the water impermeable material comprises poly(lactic acid), poly(glycolic acid), poly(hydroxybutyrate), poly(phosphazine), polyesters, polyethylene glycols, polyalkyleneoxides, polyacrylam ides, polycarbonates, polyhydroxyethylmethylacrylate, poly(vinylpyrrolidone), polyvinyl alcohols, poly(caprolactone), poly(dioxanone), polyacrylic acid, polyacetate, polypropylene, glycerols, poly(amino acids), copoly(ether-esters), polyalkylene oxalates, polyam ides, poly(iminocarbonates), polyoxaesters, polyorthoesters, polyphosphazenes and combinations thereof.
 11. The tissue thickness compensator of claim 1, wherein the at least one encapsulation comprises at least one encapsulated component comprising a haemostatic agent, an anti-inflammatory agent, an antibiotic agent, anti-microbial agent, an anti-adhesion agent, an anti-coagulant agent, a medicament, pharmaceutically active agent, and combinations thereof.
 12. The tissue thickness compensator of claim 11, wherein the anti-microbial agent comprises triclosan, chlorhexidine and its salts, silver and its salts, ammonium and its salts, copper and its salts, iron and its salts, and zinc and its salts and combinations thereof.
 13. The tissue thickness compensator of claim 1, wherein the at least one encapsulation comprises a tube comprising polyglycolic acid, polylactic acid, polydioxanone, polyhydroxyalkanoate, poliglecaprone, polycaprolactone, and combinations thereof.
 14. The tissue thickness compensator of claim 1, wherein the at least one encapsulation degrades in vivo.
 15. An article selected from an anvil of a stapling apparatus and a staple cartridge for a stapling apparatus, the article comprising the tissue thickness compensator of claim
 1. 16. The tissue thickness compensator of claim 1, wherein the temperature activatable precursor is transitioned from the inactive state to the active state prior to being implanted.
 17. A tissue thickness compensator comprising a tubular element, wherein the tubular element comprises: an inner layer comprising a temperature activatable hydrogel precursor impregnated with at least one of a haemostatic agent, an anti-inflammatory agent, an antibiotic agent, anti-microbial agent, an anti-adhesion agent, an anti-coagulant agent, a medicament, and a pharmaceutically active agent; and an outer layer comprising a water impermeable material sealingly enclosing the inner layer; wherein the temperature activatable hydrogel precursor is activatable between an inactive state and an active state prior to being implanted, and wherein the temperature activatable hydrogel precursor expands when contacted with at least one of water, saline, and a bodily fluid.
 18. The tissue thickness compensator of claim 17, wherein the temperature activatable hydrogel precursor contacts the at least one of water, saline, and a bodily fluid when the water impermeable material is ruptured, and wherein the at least one of a haemostatic agent, an anti-inflammatory agent, an antibiotic agent, anti-microbial agent, an anti-adhesion agent, an anti-coagulant agent, a medicament, and a pharmaceutically active agent is released when the water impermeable material is ruptured. 